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Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 8 Sampling Techniques and Statistical Inference Ex 8.3 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 8 Sampling Techniques and Statistical Inference Ex 8.3

Choose the correct Answer:

Question 1.
A ……………… may be finite or infinite according as the number of observation or items in it is finite or infinite
(a) Population
(b) census
(c) parameter
(d) none of these
Solution:
(a) population

Question 2.
A …………….. of statistical individuals in a population is called a sample.
(a) Infinite set
(b) finite subset
(c) finite set
(d) entire set
Solution:
(b) finite subset

Question 3.
A finite subset of statistical individuals in a population is called ………………
a) a sample
(b) a population
(c) universe
(d) census
Solution:
(a) a sample

Question 4.
Any statistical measure computed from sample data is known as ……………..
(a) Parameter
(b) random sample
(c) Infinite measure
(d) uncountable
Solution:
(b) random sample

Question 5.
A ………………. is one where each item in the universe has an equal chance of known opportu¬nity of being selected
(a) Parameter
(b) random sample
(c) statistic
(d) entire data
Solution:
(b) random sample

Question 6.
A random sample is a sample selected in such a way that every item in the population has an equal chance of being included
(a) Harper
(b) fisher
(c) karl pearson
(d) Dr. yates
Solution:
(a) Harper

Question 7.
Which one of the following is probability sampling
(a) Purposive sampling
(b) judgement sampling
(c) sample random sampling
(d) Convenience sampling
Solution:
(c) sample random sampling

Question 8.
In simple random sampling of drawing any unit, the probability of drawing any unit at the draw is ?
(a) \(\frac { n }{N}\)
(b) \(\frac { 1 }{N}\)
(c) \(\frac { N }{n}\)
(d) n
Solution:
(b) \(\frac { 1 }{N}\)

Question 9.
In ……………. the heterogeneous groups divided into homogeneous groups
(a) Non-probability sample
(b) a sample random sample
(c) a stratified random sample
(d) Systematic sample
Solution:
(c) a stratified random sample

Question 10.
Errors in sampling are of
(a) Two types
(b) three types
(c) four types
(d) five types
Solution:
(a) Two types

Question 11.
The method of obtaining the most likely value of the population parameter using statistic is called
(a) estimate
(b) estimate
(c) biased estimate
(d) standard error
Solution:
(d) standard error

Question 12.
An estimator is a sample statistic used to estimate a
(a) population parameter
(b) biased estimate
(c) sample size
(d) census
Solution:
(a) population parameter

Question 13.
…………… is a relative property, which states that one estimate is efficient relative to another.
(a) efficiency
(b) sufficiency
(c) unbiased
(d) consistency.
Solution:
(a) efficiency

Question 14.
If probability p[|\(\bar { θ }\) – θ|< ∈|< ∈|] 1 → µ as n → α for any positive then \(\bar { θ }\) is said to estimator of θ
(a) efficient
(b) sufficient
(c) unbiased
(d) consistent
Solution:
(d) Consistent

Question 15.
An estimator is said to be ………….. if it contains all the information in the data about the parameter it estimates.
(a) efficient
(b) sufficient
(c) unbiased
(d) consistent
Solution:
(b) sufficient

Question 16.
An estimate of a population parameter given by two numbers between which the parameter would be expected to lie called an ………….. interval estimate of the parameter
(a) point estimate
(b) interval estimate
(c) standard error
(d) confidence
Solution:
(b) interval estimate

Question 17.
A ……………… is a statement or an assertion about the population parameter
(a) hypothesis
(b) statistic
(c) sample
(d) census
Solution:
(a) hypothesis

Question 18.
Type I error is
(a) Accept H₀ when it is true
(b) Accept H₀ when it is false
(c) Reject H₀ when it is true
(d) Reject H₀ when it is false
Solution:
(c) Reject H₀ when it is true

Question 19.
Type II error is?
(a) Accept H₀ when it is wrong
(b) Accept H₀ when it is when it is true
(c) Reject H₀ when it is true
(d) Reject H₀ when it is false
Solution:
(a) Accept H₀ when it is wrong

Question 20.
The standard error of sample mean is?
(a) \(\frac { σ }{\sqrt{2n}}\)
(b) \(\frac { σ }{n}\)
(c) \(\frac { σ }{√n}\)
(d) \(\frac { σ^2 }{√n}\)
Solution:
(c) \(\frac { σ }{√n}\)

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 8 Sampling Techniques and Statistical Inference Ex 8.2 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 8 Sampling Techniques and Statistical Inference Ex 8.2

Question 1.
Mention two branches of statistical inference?
Solution:
(i) Estimation (ii) Testing of Hypothesis

Question 2.
What is an estimator?
Solution:
Any sample statistic which is used to estimate an unknown population parameter is called an estimator ie., an estimator is a sample statistic used to estimate a population parameter.

Question 3.
What is an estimate?
Solution:
When we observe a specific numerical value of our estimator, we call that value is an estimate. In other words, an estimate is a specific value of a statistic.

Question 4.
What is point estimation?
Solution:
When a single value as an estimate, the estimate is called a point estimate of the population parameter. In other words, an estimate of a population parameter given by a single number is called as point estimation.

Question 5.
What is interval estimation?
Solution:
Generally, there are situation where point estimation is not desirable and we are interested in finding limits within which the parameter would be expected to lie is called an interval estimation.

Question 6.
What is confidence interval?
Solution:
Let us choose a small value of a which is known as level of significance (1% or 5%) and determine two constants says c₁ and c₂ such that p(c₁ < θ < c₂|t) = 1 – α

The quantities c₁ and c₂ so determined are known as the confidence Limits and the interval [c₁, c₂] with in which the unknown value of the population parameter is expected to lie is known as confidence interval.(1 – α)is called as confidence coefficient.

Question 7.
What is null hypothesis? Give an example.
Solution:
According to prof R. A. fisher, “Null hypothesis is the hypothesis which is tested for possible rejection under the assumption that it is true”, and it is denoted by H₀.

For example: If we want to find the population mean has a specified value µ₀, then the null hypothesis H₀ is set as follows H₀ : µ = µ₀

Question 8.
Define alternative hypothesis.
Solution:
Any hypothesis which is complementry to the null hypothesis is called as the alternative hypothesis and is usually denoted by H₁.

For example: If we want to test the null hypothesis that the population has specified mean µ i.e., H₀ : µ = µ₀ then the alternative hypothesis could be any one among the following:
(i) H₁ : µ ≠ µ₀ (µ > or µ < µ₀)
(ii) H₁ : µ > µ₀
(iii) H₁ : µ < µ₀

Question 9.
Define critical region.
Solution:
A region corresponding to a test statistic in the sample space which tends to rejection of H₀ is called critical region or region of rejection.

Question 10.
Define critical value.
Solution:
The value of test statistic which separates the critical (or rejection) region and the acceptance region is called the critical value or significant value. It depend upon.
(i) The level of significance
(ii) The alternative hypothesis whether it is two-tailed or single tailed

Question 11.
Define level of significance.
Solution:
The probability of type 1 error is known as level. of significance and it is denoted by The level of significance is usually employed in testing of hypothesis are 5% and 1%. The level of significance is always fixed in advanced before collecting the sample information.

Question 12.
What is type I error
Solution:
There is every chance that a decision regarding a null hypothesis may be correct or may not be correct. The error of rejecting H₀ when it is true is called type I error.

Question 13.
What is single tailed test.
Solution:
When the hypothesis about the population parameter is rejected only for the value of sample statistic falling into one of the tails of the sampling distribution, then it is known as one-tailed test. Here H₁ : µ > µ₀ and H₁ : µ < µ₀ are known as one tailed alternative.

Question 14.
A sample of 100 items, draw from a universe with mean value 64 and S.D 3, has a mean value 63.5. Is the difference in the mean significant?
Solution:
sample size n = 100 ; sample mean \(\bar { x}\) = 63.5
sample SD S = 3;
population mean µ = 64 population SD σ = 3
Null Hypothesis H₀ : µ = 64 (the sample has been drawn from the population mean µ = 64 and SD σ = 3)
Alternative Hypothesis H₁ : µ ≠ 64 (two tail) i.e the sample has not been drawn from the population mean µ = 64 and SD σ = 3
The level of significance α = 5% = 0.05
Test statistic
z = \(\frac { 63.5-64}{\frac{3}{\sqrt{100}}}\) = \(\frac { -0.5 }{(\frac{3}{10})}\) = \(\frac { -0.5 }{0.3}\) = -1.667
|z| = 1.667
∴ calculated z = 1.667
critical value at 5% level of
significance is z_{\(\frac { α }{2}\)} = 1.96
Inference:
At 5% level of significance Z < Z_{\(\frac { α }{2}\)} since the calculated value is less than the table value the null hypothesis is accepted.

Question 15.
A sample of 400 individuals is found to have a mean height of 67.47 inches. Can it be reasonably regarded as a sample from a large population with mean height of 67.39 inches and standard deviation 1.30 inches?
Solution:
sample size n = 400; sample mean \(\bar { x}\) = 67.47 inches
sample SD S = 1.30 inches population mean
µ = 67.39 inches
population SD σ = 1.30 inches
Null Hypothesis H₀ : µ = 67.39 inches (the sample has been drawn from the population mean µ = 67.39 inches; population SD σ = 1.30 inches)
Alternative Hypothesis H₁ = µ ≠ 67.39 inches(two tail)
i.e the sample has not been drawn from the population mean µ = 67.39 inches and SD σ = 1.30 inches
The level of significance α = 5% = 0.05
Test static:

Thus the calculated and the significant value or Z_{\(\frac { α }{2}\)} = 1.96
table value comparing the calculated and table values
Z_{\(\frac { α }{2}\)} (i.e.,) 1.2308 < 1.96
Inference: since the calculated value is less than value i.e Z > Z_{\(\frac { α }{2}\)} at 5% level of significance, the null hypothesis is accepted Hence we conclude that the data doesn’t provide us any evidence against the null hypothesis. Therefore, the sample has been drawn from the population mean µ = 67.39 inches and SD σ = 1.30 inches.

Question 16.
The average score on a nationally administered aptitude test was 76 and the corresponding standard deviation was 8. In order to evaluate a state’s education system, the scores of 100 of the state’s students were randomly selected. These students had an average score of 72. Test at a significance level of 0.05 if there is a significant difference between the state scores and the national scores.
Solution:
sample size n = 100
sample mean \(\bar { x}\) = 72
sample SD S = 8
population mean µ = 76
under the Null hypothesis H₀ : p = 76
Against the alternative hypothesis H₀ : µ ≠ 76 (two mail)
Level of significance µ = 0.05
Test statistic:

since alternative hypothesis is of two tailed test we can take |Z| = 5.
∴ critical value 5% level of significance is z > z_{\(\frac { α }{2}\)} = 1.96
Inference:
Since the calculated value is less than table value i.e z > z_{\(\frac { α }{2}\)} at 5% level of significance the null hypothesis H0 is rejected Therefore, we conclude that there is significant difference between the sample mean and population mean µ = 76 and SD σ = 8.

Question 17.
The mean breaking strength of cables supplied by a manufacturer is 1,800 with a standard deviation 100. By a new technique in the manufacturing process it is claimed that the breaking strength of the cables has increased. In order to test this claim a sample of 50 cables is tested. It is found that the mean breaking strength is 1,850. Can you support the claim at 0.01 level of significance.
Solution:
Sample size n = 50
Sample mean \(\bar { x}\) = 1800
Sample SD S = 100
population mean µ = 1850
Null hypothesis H₀ : µ = 1850
Level of significance µ = 0.01

= -3.5355
∴ z = -3.536
calculated value |z| = 3.536
Critical value at 1% level of significance is z_{\(\frac { α }{2}\)} = 2.58
Inference:
Since the calculated value is greater than table (ie) z > z_{\(\frac { α }{2}\)} at 1% level of significance, the null hypothesis is rejected, therefore we conclude that we is rejected, Therefore we conclude that we can not support we conclude that we can support the claim of 0.01 of significance.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 8 Sampling Techniques and Statistical Inference Ex 8.1 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 8 Sampling Techniques and Statistical Inference Ex 8.1

Question 1.
What is population?
Solution:
The group of individuals considered under study is called as population. The word population here refers not only to people but to all items that have been chosen for the study.

Question 2.
What is sample?
Solution:
A selection of a group of observation/individuals/population in such a way that is represents the population is called as sample.

Question 3.
What is statistic?
Solution:
Statistic: Any statistical measure computed from sample is known as statistic.

Question 4.
Define parameter.
Solution:
Parameter: The statistical constants of the population like mean (µ),variance (σ²) are referred as population parameters.

Question 5.
What is sampling distribution of a statistic?
Solution:
Sampling distribution of a statistic is the frequency distribution which is formed with various of a statistic computed from different samples of the same size drawn from the same population.

Question 6.
What is standard error?
Solution:
The standard deviation of the sampling distribution of a statistic is known as its Standard Error abbreviated as S.E.

Question 7.
Explain in detail about simple random sampling with a suitable example.
Solution:
In this technique the samples are selected in such a way that each and every unit in the population has an equal and independent chance of being selected as a sample. Simple random sampling may be done, with or without replacement of a samples selected. In a simple random sampling with replacement there is a possibility of selecting the same sample any number of times. So, simple random sampling without replacement is followed. Thus in simple random sampling from a population of N units ,the probability of drawing any unit at the first draw is \(\frac { 1 }{N}\), the probability of drawing any unit in the second draw from among the available (N – 1) units is \(\frac { 1 }{(N-1)}\), and so on.

For example, if we want to select 10 students, out of 100 students, then we must write the names/roll number of all the 100 students on slips of the same size and mix them, then we make a blindfold selection of 10 students. This method is called unrestricted random sampling, because units are selected from the population without any restriction. This method is mostly used in lottery draws. If the population or universe is infinite, this method is inapplicable.

Question 8.
Explain the stratified random sampling with a suitable example.
Solution:
In stratified random sampling, first divide the population into sub-populations, which are called strata. Then,the samples are selected from each of the strata through random techniques. The collection of all the samples from all strata gives the stratified random samples.

When the population is heterogeneous or different segments or groups with respect to the variable or characteristic under study, then stratified Random sampling methos is studied. First, the population is divided into homogeneous number of sun-groups of strata before the sample is drawn. A sample from each stratum at random. Following steps are involved for selecting random sample in a stratified random sampling method.

(a) The population is divided into different classes so that each stratum will consist of more or less homogeneous elements. The strata are so designed that they do not overlap each other.

(b) After the population is stratified,a sample of a specified size is drawn at random from each stratum using Lottery Method or table of random number method.

Question 9.
Explain in detail about systematic random sampling with example.
Solution:
In a systematic sampling, randomly select the first sample from the first k units. Then every k th members, starting with the first selected sample, is included in the sample.

Systematic sampling is a commonly used technique,if the complete and up-to-date list of the sampling units is available. We can arrange the items in numerical, alphabetical, selecting the first at random, the rest being automatically selected according to some pre-determined pattern. A systematic is formed by selecting every item from the population, where k refers to the sample interval. The sampling interval can be determined by divided the size of the population by the size of the sample to be chosen.

That is K = \(\frac { N }{n}\), where k is an integer.
k = sampling interval, size of the population, sample size
Procedure for selection of samples by systematic sampling method

(i) If we want to select a sample of 10 students from a class of 100 students,the sampling interval is Calculated as k = \(\frac { N }{n}\) = \(\frac { 100 }{10}\) = 10
Thus sampling interval = 10 denotes that for every 10 samples one sample

(ii) The first sample is selected from the first 10(sampling interval) samples through selection procedures.

(iii) If the selected first random sample is 5, then the rest of the samples are automatically selected by incriminating the value of the sampling interval 9k = 10. i.e, 5, 15, 25, 35, 45, 55, 65, 75, 85, 95.

Question 10.
Explain in detail about sampling error.
Solution:
Sampling Error:
Error, which arise in the normal course of investigation or enumeration on account of chance, are called sampling errors, sampling errors are inherent in the method of sampling. They may arise accidentally without any bias or prejudice. Sampling Errors arise primarily due to the following reasons:
(a) Faulty selection of the sample instead of correct sample by defective sampling technique.
(b) The investigator substitutes a convenient sample if the original sample is not available while investigation.
(c) In area surveys,while dealing with border lines it depends upon the investigator whether to include them in the sample or not. This is known as faulty demarcation of sampling units.

Question 11.
Explain in detail about non-sampling error.
Solution:
Non-sampling Errors:
The errors that arise due to human factors which always vary from one investigator to another in selecting, estimating or using measuring instruments (tape, scale) are called Non¬sampling errors. It may arise in the following ways:
(a) Due to neglience and carelessness of the part of either investigator or respondents
(b) Due to lack of trained and qualified investigators.
(c) Due to framing of a wrong questionnaire.
(d) Due to apply wrong statistical measure.
(e) Due to incomplete investigation and sample survey.

Question 12.
State any two merits of simple random sampling.
Solution:
Merits:
1. Personal bias is completely eliminated.
2. This method is economical as it saves time, money and labour.
3. The method requires minimum knowledge about the population in advance.

Question 13.
State any three merits of stratified random sampling.
Solution:
Merits:
(a) A random stratified sample is superior to a sample random sample because it ensures representation of all groups and thus it is more representative of the population which is being sampled.
(b) A stratified random sample can be kept small in size without losing its accuracy
(c) it is easy to administer, if the population under study is sub divided
(d) It reduces the time and expenses in dividing the strata into geographical divisions, since the government itself had the geographical areas.

Question 14.
State any two demerits of systematic random sampling.
Solution:
Demerits:
1. Systematic samples are not random samples.
2. If N is not multiple of n-then the sampling interval (k) cannot be an integer, thus sample selection becomes difficult.

Question 15.
State any two merits for systematic random sampling.
Solution:
Merits:
1. This is simple and convenient method.
2. This method distributes the sample more evenly over the entire listed population.
3. The time and work is reduced much.

Question 16.
Using the following Tippet’s random number table

Draw a sample of 10 three digit numbers which are even numbers.
Solution:
There are many ways to select 10 random samples from the given Tippets random number number table since the population size is three digit numbers, Here the door numbers must be even (ie) the unit digit must be even. Here we consider column wise selection of random numbers starting from first column.

So the first sample is 416 and other 9 samples are 056, 664, 952, 748, 524, 914, 154, 340 and 140.
Tippets random number Table

Question 17.
A wholesaler in apples claims that only 4% of the apples supplied by him are defective. A random sample of 600 apples contained 36 defective apples. Calculate the standard error concerning of good apples.
Solution:
sample size = 600; Number of success = 600 – 36
= 564
sample proportion p = \(\frac { 564 }{600}\) = 0.94
600
population proportion (p) = probability of getting good apple
= 96%
= \(\frac { 96 }{100}\) {∵ 4% of the apples 100 are defective}
P = 0.96
Q = 1 – p = 1 – 0.96
Q = 0.04
The S.E for a sample proporation is given by
S.E = \(\sqrt{\frac { PQ }{N}}\) = \(\sqrt{\frac { (0.96)(0.04) }{600}}\)
\(\sqrt{\frac { 0.0384 }{600}}\) = \(\sqrt{0.000064}\)
∴ S.E = 0.008
Hence the standard error foe sample proportion is S.E = 0.008

Question 18.
A sample of 1000 students whose mean weight is 119 lbs (pounds) from a school in Tamil Nadu State was taken and their average weight was found to be 120 lbs with a standard deviation of 30 lbs. Calculate standard error of mean.
Solution:
Given n = 1000; \(\bar{x}\) = 119 lbs (pounds)
s = 30 lbs is known in this problem.
since σ is unknown, so we consider \(\bar{σ}\) = s and µ = 120 lbs
S.E = \(\frac { \bar{σ} }{√n}\) = \(\frac { s }{√n}\) = \(\frac { 30 }{\sqrt{1000}}\)
= \(\frac { 30 }{31.623}\) = 0.9487
Therefore the standard error for the average weight of large group of students of 120 lbs is 0.9487

Question 19.
A random sample of 60 observations was drawn from a large population and its standard deviation was found to be 2.5. Calculate the suitable standard error that this sample is taken from a population with standard deviation 3?
Solution:
Sample size n = 60
Sample S.D S = 2.5
population S.D a = 3
The standard error for sample S.D is given by
\(\sqrt{\frac { σ^2 }{2n}}\) = \(\sqrt{\frac { (3)^2 }{2(60)}}\) = \(\frac { 3 }{\sqrt{120}}\)
= \(\frac { 3 }{10.954}\) = 0.27387
= 0.2739
Thus standard error for sample S.D = 0.2739

Question 20.
In a sample of 400 population from a village 230 are found to be eaters of vegetarian items and the rest non-vegetarian items. Compute the standard error assuming that both vegetarian and non-vegetarian foods are equally popular in that village?
Solution:
sample size n = 400
case (i):
sample proporation of vegetarian p = \(\frac { 3 }{10.954}\) = \(\frac { 230 }{400}\)
p = 0.575
q = 1 – p
= 1 – 0.575
q = 0.425
Sample error S.E= \(\sqrt{\frac { pq }{n}}\)
= \(\sqrt{\frac { 0.575×0.425 }{400}}\) = \(\sqrt{\frac { 0.223125 }{400}}\)
\(\sqrt{0.0005578125}\)
S.E = 0.2361

Case(ii):
sample size n = 400
since both vegetarian and non- vegetarian foods are equally popular in that village
sample proparation of vegetarian p = \(\frac { 1 }{2}\) = 0.5
q = 1 -p ⇒ q = 1 – 0.5
q = 0.5

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 7 Probability Distributions Ex 7.4 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 7 Probability Distributions Ex 7.4

Choose the correct answer

Question 1.
Normal distribution was invented by
(a) Laplace
(b) De-Moivre
(c) Gauss
(d) all the above
Solution:
(b) Demoivre

Question 2.
If X ~ N(9, 81) the standard normal variate Z will be
(a) Z = \(\frac { X-81 }{9}\)
(b) Z = \(\frac { X-9 }{81}\)
(c) Z = \(\frac { X-9 }{9}\)
(d) Z = \(\frac { 9-X }{9}\)
Solution:
(b) Z = \(\frac { X-9 }{81}\)
Hint:
Here µ = 9
σ² = 81
∴ σ = 9
Z = \(\frac { X-µ }{σ}\) = \(\frac { X-9 }{9}\)

Question 3.
If Z is a standard normal variate, the proportion of items lying between Z = -0.5 and Z = -3.0 is
(a) 0.4987
(b) 0.1915
(c) 0.3072
(d) 0.3098
Solution:
(c) 0.3072
Hint:

p(-3.0 < z < -0.5)
= p(0.5 < z < 3.0) – p(0 < z < o.5)
= 0.4987 – 0.1915 = 0.3072

Question 4.
If X ~ N(µ, σ2), the maximum probability at the point of inflexion of normal distribution
(a) (\(\frac { 1 }{\sqrt{2π}}\))e^{\(\frac { -1 }{2}\)}
(b) (\(\frac { 1 }{\sqrt{2π}}\))e^{\(\frac { 1 }{2}\)}
(c) (\(\frac { 1 }{σ\sqrt{2π}}\))e^{\(\frac { -1 }{2}\)}
(d) (\(\frac { 1 }{\sqrt{2π}}\))
Solution:
(c) (\(\frac { 1 }{σ\sqrt{2π}}\))e^{\(\frac { -1 }{2}\)}

Question 5.
In a parametric distribution the mean is equal to variance is
(a) binomial
(b) normal
(c) poisson
(d) all the above
Solution:
(c) poisson

Question 6.
In turning out certain toys in a manufacturing company, the average number of defectives is 1%. The probability that the sample of 100 toys there will be 3 defectives is
(a) 0.0613
(b) 0.613
(c) 0.00613
(d) 0.3913
Solution:
(a) 0.0613
Hint:
Given
p = 0.01 and n = 100
λ = np = 0.01 × 100 = 1
p(x = x) = \(\frac { e^{-λ}λ^x }{x!}\)
p(x = x) = \(\frac { e^{-1}(1)^3 }{3!}\) = \(\frac { 0.3678 }{6}\) = 0.0613

Question 7.
The parameters of the normal distribution
f(x) (\(\frac { 1 }{\sqrt{72π}}\)) \(\frac { e^{-(x-10)^2} }{72}\) – ∞ < x < ∞
(a) (10, 6)
(b) (10, 36)
(c) (6, 10)
(d) (36, 10)
Solution:
(b) (10, 36)
Hint:

Here σ = 6 and µ = 10
∴ σ = (6)² = 36

Question 8.
A manufacturer produces switches and experiences that 2 per cent switches are defective. The probability that in a box of 50 switches, there are at most two defective is:
(a) 2.5 e^-1
(b) e^-1
(c) 2 e^-1
(d) none of the above
Solution:
(a) 2.5 e^-1
Hint:

Question 9.
An experiment succeeds twice as often as it fails. Die chance that in the next six trials, there shall be at least four successes is
(a) 240/729
(b) 489/729
(c) 496/729
(d) 251/729
Solution:
(c) 496/729
Hint:
p = 2 q ⇒ p = 2(1 – p)
p (2 – 2p) ⇒ 3p = 2
p = 2/3 and q = 1 – p ⇒ q = 1 – 2/3
q = 1/3 and n = 6
p(X = x) = nc_xp^xq^n-x
p(x ≥ 4) = p(x = 4) + p(x = 5) + p(x = 6)

Question 10.
If for a binomial distribution b(n, p) mean = 4 and variance = 4/3, the probability, P(X ≥ 5) is equal to:
(a) (2/3)⁶
(b) (2/3)⁵( 1/3)
(c) (1/3)⁶
(d) 4(2/3)⁶
Solution:
(d) 4(2/3)⁶
Hint:
In a binomial distribution
mean np = 4 → (1)
variance npq = 4/3 → (2)
(2) ÷ (1) ⇒ npq = 4/3 ⇒ q = 1/3
p = (1 – q) ⇒ p = 1 – 1/3
∴ p = 2/3
p(X = x) = nc_rp^xq^n-x
p(x ≥ 5) = p(x = 5) + p(x = 6)

Question 11.
The average percentage of failure in a certain examination is 40. The probability that out of a group of 6 candidates atleast 4 passed in the examination are:
(a) 0.5443
(b) 0.4543
(c) 0.5543
(d) 0.4573
Solution:
(b) 0.4543
Hint:
given:
n = 6
q = 40/100 = 2/5
p = 1 – q = 1 – 2/5 = 3/5
p(X = x) = nc_xp^xq^n-x
p(x ≥ 4) = p(x = 4) + p(x = 5) + p(x = 6)

= \(\frac { 8505 }{5^6}\) = \(\frac { 1701 }{3125}\)
= 0.54432

Question 12.
Forty percent of the passengers who fly on a certain route do not check in any luggage. The planes on this route seat 15 passengers. For a full flight, what is the mean of the number of passengers who do not check in any luggage?
(a) 6.00
(b) 6.45
(c) 7.20
(d) 7.50
Solution:
(a) 6.00
Hint:
Given
P = \(\frac { 40 }{100}\) and n = 15
Mean np = \(\frac { 40 }{100}\) × 15
= 0.4 × 15
= 6.00

Question 13.
Which of the following statements is/are true regarding the normal distribution curve?
(a) it is symmetrical and bell shaped curve
(b) it is asymptotic in that each end approaches the horizontal axis but never reaches it
(c) its mean, median and mode are located at the same point
(d) all of the above statements are true.
Solution:
(d) all of these above statements are true

Question 14.
Which of the following cannot generate a Poisson distribution?
(a) The number of telephone calls received in a ten-minute interval
(b) The number of customers arriving at a petrol station
(c) The number of bacteria found in a cubic feet of soil
(d) The number of misprints per page
Solution:
(b) The number of customers arriving a petrol station

Question 15.
The random variable X is normally distributed with a mean of 70 and a standard deviation of 10. What is the probability that X is between 72 and 84?
(a) 0.683
(b) 0.954
(c) 0.271
(d) 0.340
Solution:
(d) 0.340
Hint:
In a normal distribution
S.D(σ) = 10
mean(µ) = 70 and

= p(0.2 < z < 1.4) – p(0 < z < 0.2)
= 0.4192 – 0.0793
= 0.3399

Question 16.
The starting annual salaries of newly qualified chartered accountants (CA’s) in South Africa follow a normal distribution with a mean of Rs 180,000 and a standard deviation of Rs 10,000. What is the probability that a randomly selected newly qualified CA will earn between Rs 165,000 and Rs 175,000 per annum?
(a) 0.819
(b) 0.242
(c) 0.286
(d) 0.533
Solution:
(b) 0.242
Hint:
In a normal distribution
µ = 180,000 and σ = 10,000
z = \(\frac { X-µ }{σ}\) = \(\frac { X-180000 }{10000}\)
p(165,000 < x < 1,75,000) = ?
when x = 165,000
z = \(\frac { 165000-180000 }{10000}\) = \(\frac { 15000 }{10000}\)
z = -1.5

when x = 175,000
z = \(\frac { 175000-180000 }{10000}\) = \(\frac { -5000 }{10000}\) = \(\frac { -1 }{2}\)
z = -0.5
p(165,000 < x < 175,000)
= p(-1.5 < z < -0.5)
= p(0.5 < z < 1.5)
= p(0 < z < 1.5) – p(0 < z < 0.5)
= 0.4332 – 0.1915 = 0.2417

Question 17.
In a large statistics class the heights of the students are normally distributed with a mean of 172 cm and a variance of 25 cm. What proportion of students are between 165 cm and 181 cm in height?
(a) 0.954
(b) 0.601
(c) 0.718
(d) 0.883
Solution:
(d) 0.883
Hint:

In a normal distribution
µ = 172; σ² = 25 then σ = 5
z = \(\frac { x-µ }{σ}\) = \(\frac { x-172 }{5}\)
p(165 < x < 181) = ?
when x = 165 z = \(\frac { 165-172 }{5}\) = \(\frac { -7 }{5}\) = -1.4
when x = 181 z = \(\frac { 181-172 }{5}\) = \(\frac { 9}{5}\) = 1.8
p(165 < x < 181) = p(-1.4 < z < 1.8)
= p(-1.4 < z < 0) + p(0 < z < 1.8)
= p(0 < z < 1.4) + p(0 < z < 1.8)
= 0.4192 + 0.4641
= 0.8833

Question 18.
A statistical analysis of long-distance” telephone calls indicates that the length of these calls is normally distributed with a mean of 240 seconds and a standard deviation of 40 seconds. What proportion of calls lasts less than 180 seconds?
(a) 0.214
(b) 0.094
(c) 0933
(d) 0.067
Solution:
(d) 0.067
Hint:
In a normal distribution

µ = 240 and σ = 40

Question 19.
Cape town is estimated to have 21% of homes whose owners subscribe to the satelite service, DSTV. If a random sample of your home in taken, what is the probability that all four home subscribe to DSTV?
(a) 0.2100
(b) 0.5000
(c) 0.8791
(d) 0.0019
Solution:
(d) 0.0019
Hint:
p = \(\frac { 21 }{100}\) = 0.21
p(x = 4) = (0.21) × (0.21) × (0.21) × (0.21)
= 0.00194481

Question 20.
Using the standard normal table, the sum of the probabilities to the right of z = 2.18 and to the left of z = -1.75 is:
(a) 0.4854
(b) 0.4599
(c) 0.0146
(d) 0.0547
Solution:
(d) 0.0547
Hint:

p(z < – 1.75) + p(z > 2.18)
= p(-∞ < z < 0) – p(-1.75 < z < 0) + p(0 < z < ∞) – p(0 < z < 2.19)
= 0.5 – p(0 < z < 1.75) + 0.5 – p(0 < z < 2.18)
= (0.5 – 0.4599) + (0.5 – 0.4854)
= 0.0401 + 0.0146
= 0.0547

Question 21.
The time until first failure of a brand of inkjet printers is normally distributed with a mean of 1,500 hours and a standard deviation of 200 hours. What proportion of printers fails before 1000 hours?
(a) 0.0062
(b) 0.0668
(c) 0.8413
(d) 0.0228
Solution:
(a) 0.0062
Hint:

Question 22.
The weights of newborn human babies are normally distributed with a mean of 3.2 kg and a standard deviation of 1.1 kg. What is the probability that a randomly selected newborn baby weighs less than 2.0 kg?
(a) 0.138
(b) 0.428
(c) 0.766
(d) 0.262
Solution:
(a) 0.138
Hint:

Question 23.
Monthly expenditure on their credit cards, by credit card holders from a certain bank, follows a normal distribution with a mean of Rs 1,295.00 and a standard deviation of Rs 750.00. What proportion of credit card holders spend more than Rs 1,500.00 on their credit cards per month?
(a) 0.487
(b) 0.392
(c) 0.500
(d) 0.791
Solution:
(b) 0.392
Hint:
In a normal distribution

mean m = 1295 and S.D σ = 7.50
p(x > 1500) = ?
when x = 1500
z = \(\frac { 1500-1295 }{750}\) = \(\frac { 205 }{750}\) = 0.273
(ie) p(x > 1500) = p(z > 0.273)
= 0.5 – p(0 < z < 0.273)
= 0.5 – 0.1064
= 0.3936

Question 24.
Let z be a standard normal variable. If the area to the right of z is 0.8413, then the value of z must be:
(a) 1.00
(b) -1.00
(c) 0.00
(d) -0.41
Solution:
(b) -1.00
Hint:

p(-c < z < ∞) = 0.8413
p(-c < z < 0) + 0.5 = 0.8413
p(-c < z < 0) = 0.813 – 0.5 = 0.3413
p(0 < z < c) = 0.3413 ⇒ c = 1.00
∴ -c = -1.00

Question 25.
If the area to the left of a value of z (z has a standard normal distribution) is 0.0793, what is the value of z?
(a) -1.41
(b) 1.41
(c) -2.25
(d) 2.25
Solution:
(a) -1.41
Hint:

p(z < -c) = 0.0793 ie p(z > c) = 0.0793
p(0 < z < ∞) – p(0 < z < c) = 0.0793
0. 5 – p(0 < z < c) = 0.0793
p(0 < z < c) = 0.5 – 0.0793
p(0 < z < c) = 0.4207
c = 1.41
then -c = -1.41

Question 26.
If P(Z > z) = 0.8508 what is the value of z (z has a standard normal distribution)?
(a) -0.48
(b) 0.48
(c) -1.04
(d) 1.04
Solution:
(c) -1.04
Hint:
since the area is greater than 0.5 then the z must be negative

p(z < Z) = 0.8508
p(-z < Z < 0) + p(0 < z < ∞) = 0.8508
p(-z < Z < 0) + 0.5 = 0.8508
p(-z < Z < 0) = 0.8508 – 0.5 = 0.3508
p(0 < Z < z) = 0.3508
z = 1.04 then -z = -1.04

Question 27.
If P(Z > z) = 0.5832 what is the value of z (z has a standard normal distribution)?
(a) -0.48
(b) 0.48
(c) 1.04
(d) -0.21
Solution:
(d) -0.21
Hint:
p(z > Z) = 0.5832
since area >0.5 then then z must be negative

p(- z < Z < ∞) = 0.5832
p(-z < Z < 0) + p(0 < Z < ∞) = 0.5832
p(-z < Z < 0) + 0.5 = 0.5832
p(-z < Z < 0) = 0.0832
z = 0.21
then -z = -0.21

Question 28.
In a binomial distribution, the probability of success is twice as that of failure. Then out of 4 trials, the probability of no success is
(a) 16/81
(b) 1/16
(c) 2/27
(d) 1/81
Solution:
(d) 1/81
Hint:
In a binomial distribution
p = 2q ⇒ p = 2(1 – p)
p = 2 – 2p ⇒ 3p = 2 ⇒ p = 2/ 3
q = 1 – p = 1 – 2/3
∴ q = 1/3
p(X = x) = nc_xp^xq^n-x = 4c_x (\(\frac { 2 }{3}\))^x (\(\frac { 1 }{3}\))^4-x
p(X = 0) = 4c₀ (\(\frac { 2 }{3}\))⁰ (\(\frac { 1 }{3}\))^4-0
= (1)(1)(\(\frac { 1 }{3}\))⁴ = \(\frac { 1 }{81}\)

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 12 Trends in Economic Zoology Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter Chapter 12 Trends in Economic Zoology

11th Bio Zoology Guide Trends in Economic Zoology Text Book Back Questions and Answers

Part I

Question 1.
Which one of the following is not related to vermiculture?
a) Maintains soil fertility
b) Break down of inorganic matter
c) Gives porosity, aeration and moister holding capacity
d) Degradation of non biodegradable solid waste

a) a and b is correct
b) c and d is correct
c) b and d is not correct
d) a and c is not correct
Answer:
c) b and d is not correct

Question 2.
Which one of the following is not an endemic species of earthworm?
a) Perionyx
b) Lampito
c) Eudrillus
d) Octochaetona
Answer:
c) Eudrillus

Question 3.
Match the following
1) Bombyxmori-
a) Champa – I) Muga
2) Antheraeaassamensis
b) Mulberry – II) Eri
3) Antheraeamylitta-
c) Arjun – III) Tassar
4) Attacus ricini –
d) Castor – IV) Mulberry

Select the correct one
a) 1-b-IV
b) 2-a-I
c) 3-c -III
d) 4-d-II
Answer:
c) 3-c -III

Question 4.
Silk is obtained from
a) Laccifer lacca
b) Nosema bombycis
c) Attacus ricird
d) Attacus mylitta
Answer:
c) Attacus ricird

Question 5.
Assertion: Nuptial flight is a unique flight taken by the queen bee followed by serveral drones.
Reason: The queen bee produces a chemical substance called pheromone. The drones in that area are attracted to the pheromone and then mating takes place.
a) Assertion and reason is correct but not related
b) Assertion and reason is incorrect but related
c) Assertion and reason is correct but related
d) Assertion and reason is incorrect but not related
Answer:
c) Assertion and reason is correct but related

Question 6.
Rearing of honey bee is called
a) Sericulture
b) Lac culture
c) Vermiculture
d) Apiculture
Answer:
d) Apiculture

Question 7.
Which of the statement regarding Lac insect
a) A microscopic, resinous crawling scale insect
b) Inserts its proboscis into plant tissue suck juices and grows
c) Secretes lac from the hind end of body.
d) The male lac insect is responsible for large scale production of lac.
Answer:
d) The male lac insect is responsible for large scale production of lac.

Question 8.
Aquaponics is a technique which is
a) A combination of aquaculture and fish culture
b) A combination of aquaculture and hydroponics
c) A combination of vermiculture and hydroponics
d) A combination of aquaculture and prawn culture
Answer:
b) A combination of aquaculture and hydroponics

Question 9.
Prawn belongs to the class
a) Crustacea
b) Annelida
c) Coelenterata
d) Echinodermata
Answer:
a) Crustacea

Question 10.
Pearl oyster belongs to the class
a) Gastropoda
b) Cephalopoda
c) Scaphapoda
d) Pelecypoda
Answer:
d) Pelecypoda

Question 11.
Inland fisheries are
a) deep sea fishing
b) capturing fishes from sea coast
c) Raising and capturing fishes in fresh water
d) oil extraction from fish
Answer:
c) Raising and capturing fishes in fresh water

Question 12.
Induced breeding technique is used in
a) Marine fishery
b) Capture fishery
c) Culture fishery
d) Inland fishery
Answer:
d) Inland fishery

Question 13.
Isinglass is used in
a) Preparation
b) Clearing of wines
c) Distillation of wines
d) Preservation of wines
Answer:
b) Clearing of wines

Question 14.
Animal husbandry is the science of rearing, feeding and caring, breeding and disease control of animals. It ensures supply of proper nutrition to our growing population through activities like increased production and improvement of animal products like milk, eggs, meat, honey etc.
a) Poultry production depends upon the photoperiod. Discuss
b) Polyculture of fishes is of great importance.
Answer:
a) Poultry production depends upon the photoperiod:

• The photoperiod stimulates the growth and breeding of birds.
• It increases the life span of birds
• As it increases the metabolic rate the egg-laying fowl’s wifi lay more eggs.
• The light induces the endocrine glands and increases hormone secretion.
• The light intensity depends on its wavelengths.

b) Polyculture of fishes is of great importance:

• In polyculture, fishes will not fight for food.
• No deficiency of oxygen.
• In this culture the upper layer fishes feeds on phy to and zooplanktons the middle layer fishes feeds on
• submerged plants and fishes lives in the deeper layers feeds on bottom dwellers debris of plants and animals.
• In polyculture the fishes use the maximum food to convert it into meat.
• Fishes have high growth rate in short periods.
  Eg.: Catlacatla, cirrhinus mrigla labeorohita are cultured through polyculture.

Question 15.
Assertion: The best quality of pearl is known as lingha pearl and obtained from marine oysters.
Reason: Nacre is secreted continuously by the epithelial layer of the mantle and deposited around the foreign particle
a) Assertion is true Reason is false
b) Assertion and Reason is false
c) Asserion is false but Reason is true
d) Assertion and Reason are true
Answer:
d) Assertion and Reason are true

Question 16.
Choose the correctly matched pair
a) Egg layers-Brahma
c) Dual purpose-White plymouth rock
b) Broiler types -Leghorn
d) Ornamental breeds -Silkie
Answer:
d) Ornamental breeds -Silkie

Question 17.
Write the advantages of vermicomposting.
Answer:

1. Vermicomposting provides excellent organic manure for sustainable agro-practices.
2. Marketing of vermicompost can provide a supplementary income.
3. Vermicompost is rich in essential plant nutrients.
4. It improves soil structure, texture, aeration, and water holding capacity and prevents soil erosion.
5. It is rich in nutrients and an eco-friendly amendment to soil for farming and terrace gardening,
6. It enhances seed germination and ensures good plant growth.

Question 18.
Name the three castes in a honey bee colony.
Answer:

1. Queen bee
2. Drone
3. Worker bee

Question 19.
Name the following

1. The largest bee in the colony:
2. The kind of flight which the new virgin queen takes along with the drones out of the hive:

Answer:

1. The largest bee in the colony – The queen bee
2. The kind of flight which the new virgin queen takes along with the drones out of the hive – Nuptial flight.

Question 20.
What are the main duties of a worker bee?
Answer:
Each worker has to perform different types of work in her lifetime. During the first half of her life, she becomes a nurse bee attending to indoor duties such as secretion of royal jelly, prepares bee- bread to feed the larvae, feeds the queen, takes care of the queen and drones, secretes beeswax, builds combs, cleans and fans the beehive. Then she becomes a soldier and guards the beehive. In the second half of her life lasting for three weeks, she searches and gathers the pollen, nectar, propolis, and water.

Question 21.
What happens to the drones after the mating flight?
Answer:
The drones are attracted to the pheromones of the queen bee and mating taking place The drone dies after copulation

Question 22.
Give the economic importance of silkworm?
Answer:

1. Rearing of silkworm on a commercial scale is called sericulture.
2. It is an agro-based industry comprising of
   • Cultivation of food plants for the silkworms.
   • Rearing of silkworms.
   • Reeling and spinning of silk.
3. Silk fibres are utilized in preparing silk clothes.
4. Silk is used in industries and for military purposes.
5. Silk is used in the manufacture of fishing fibres, parachutes, cartridge bags, insulation coils for telephone, wireless receivers, tyres of racing cars, filter fibres, in medical dressings and suture materials.

Question 23.
What are the nutritive values of fishes?
Answer:

• Fishes form a rich source of protein food.
• It is a good stable food to tide over the nutritional needs of man.
• Fish species such as sardines mackeral, tuna herrings have high amino acid concentrations.
• They have histidine which is responsible for the meaty flavor of the flesh.
• It is rich in omega 3 fatty acids.
• Minerals such as calcium magnesium phosphorus potassium iron-manganese iodine and copper is present in fishes.

Question 24.
Give the economic importance of prawn fishery?
Answer:
The flesh of prawns is palatable and rich in glycogen, a protein with low-fat content.

Question 25.
Give the economic importance of lac insect.
Answer:

• Lac is used as a sealing wax and adhesive for optical instruments.
• It is a good insulator.
• It is used in the preparations of shoe and leather polishes and as a protective coating of wood.
• It is used in laminating paper board photographs, plastic moulded articles.
• Used as a filling material for gold ornaments.

Question 26.
List any three common uses of shellac.
Answer:

1. Shellac with denatured alcohol is used to remove dust on the walls.
2. Coating of metals with shellac prevents rusting.
3. Shellac coating on citrus fruits increases their shelf life.

Question 27.
Name any two trees on which lac insect grows?
Answer:

1. Acacia catechu
2. Acacia nilotica

Question 28.
What is seed lac?
Answer:
The lac after grinding the dust particles are removed. The resultant lac is called ‘seed lac’.

Question 29.
Define cross-breeding?
Answer:
Breeding between a superior male of one breed with a superior female of another breed is known as cross-breeding.

Question 30.
What are the advantages of artificial insemination?
Answer:

• It increases the rate of conception.
• It avoids genital diseases.
• Semen can be collected from injured bulls which have desirable traits.
• Superior animals located apart can be bred successfully.

Question 31.
Discuss the various techniques adopted in cattle breeding?
Answer:
There are two methods of animal breeding, namely inbreeding and outbreeding.
1. Inbreeding:
Breeding between animals of the same breed for 4-6 generations is called inbreeding.

2. Outbreeding:
The breeding between unrelated animals is called outbreeding. It is done in three ways;

• Outcrossing: It is the breeding between unrelated animals of the same breed but having no common ancestry. The offspring of such a cross is called an outcross.
• Crossbreeding: Breeding between a superior male of one breed with a superior female of another breed. The cross-bred progeny has superior traits (hybrid vigour or heterosis).
• Interspecific hybridization: In this method of breeding mating is between male and females of two different species.

Question 32.
Mention the advantages of MOET.
Answer:
The advantage of this technology is to produce high milk-yielding females and high-quality meat-yielding bulls in a short time.

Question 33.
Write the peculiar characters of the duck.
Answer:
The peculiarity of ducks:
The ducks body is fully covered with oily feathers. They have a layer of fat under their skin which prevents it from getting wet. They lay eggs at night or in the morning. The ducks feed on rice bran, kitchen wastes, waste fish, and snails.

Part – II

11th Bio Zoology Guide Trends in Economic Zoology Additional Important Questions and Answers

I. Choose The Best Options

Question 1.
What is the primary use of earthworm?
a) Vermicompost
b) Increase the agriculture
c) To increase the fish culture
d) All the above
Answer:
a) Vermicompost

Question 2.
Who has proposed the term vermi tech?
a) Sultan Ismail
b) Darwin
c) Linnaeus
d) Albert William
Answer:
a) Sultan Ismail

Question 3.
……………………. are the biological indicators of soil fertility?
a) Vermicast
b) Earthworm
c) Vermi excreta
d) Vermicompost
Answer:
b) Earthworm

Question 4.
Which of the following is the earthworm of the native soil?
a) Periyonx Eisenia
b) Eudrilus eugeniae lampito mauritii
c) Periyonyx excavatus, octohaetona
d) all the above
Answer:
c) Periyonyx excavates, octohaetona

Question 5.
Which is called commercial fibre?
a) Silk fibre
b) Nylon fibre
c) Cofton fibre
d) Jute fibre
Answer:
a) Silk fibre

Question 6.
Who has known the utility of silk even before 3000 years?
a) Europe
b) African’s
c) China
d) India
Answer:
c) China

Question 7.
…………………… More than countries in the world are practicing sericulture?
a) 29
b) 40
c) 10
d) 15
Answer:
a) 29

Question 8.
Match and find the correct sequences.
I. Bombyx mori – a) Erisilk
II. Antheraea assamensis – b) Tisaarsilk
III. Antheraea mylitta – c) Mugasilk
IV. Attacus ricini – d) Mulberry silk

Answer:
a) I – d, II – c, III – b, IV – a

Question 9.
Match the silk moth with their respective leaves.
I. Bombyx mori – a) Castor
II. Antheraea assamensis – b) Arjun
III. Antheraea mylitta – c) Champa
IV. Attacus ricini – d) Mulberry


Answer:
a) I -d, II – c, III – b, IV – a

Question 10.
Find the unrelated pair regarding the silk production and its states.
a) Karnataka – Mulberry silk
b) Manipur – Muga silk
c) West bengal – Tasar silk
d) Arunachala pradesh – Muga silk
Answer:
d) Arunachala pradesh – Muga silk

Question 11.
Name the branches that involve agriculture and industry.
a) Vermiculture
b) Pisciculture
c) Sericulture
d) Poultry
Answer:
c) Sericulture

Question 12.
Life span of Bombyxmori
a) 2-3 days
b) 2 – 4 days
c) 2-5 days
d) 4 – 7 days
Answer:
a) 2 – 3 days

Question 13.
What is the number of eggs laid by Bombyx mori once?
a) 500 – 800
b) 400 – 500
c) 400 – 450
d) 600-700
Answer:
b) 400 – 500

Question 14.
What is the length of matured silkworm?
a) 7.5 cm
b) 7cm
c) 8.5 cm
d) 8 cm
Answer:
a) 7.5 cm

Question 15.
What would be the length of silk fibre in a cocoon?
a) 1000-1100 m
b) 1000-1200 m
c) 1000-1500m
d) 1000 – 1300m
Answer:
b) 1000 – 1200m

Question 16.
What is meant by mariculture?
a) Rearing of mulberry plants
b) Rearing of castor plants
c) Vermiculture
d) Apiculture
Answer:
a) Rearing of mulberry plants

Question 17.
What is meant by voltinism?
a) No of broods raised
b) Cocoon
c) Spinneret
d) None of the above
Answer:
a) No of broods raised

Question 18.
What is the ideal period for mulberry culture?
a) January, February, and November, December
b) March, April and June, July
c) June, July, and Nov, December
d) October, November and December, January
Answer:
c) June, July, and November, December

Question 19.
Find the odd one out.
a) Healthy silk moths are allowed to mate for 4 hours
b) Female lays about 400 eggs in 24 hours
c) The small larvae hatch between 7-10 days after incubation
d) The optimum temperature for rearing silk moth is 25°C – 30°C
Answer:
d) The optimum temperature for rearing silk moth is 25°C – 30°C

Question 20.
Silkmoth matured in about days
a) 40 days
b) 45 days
c) 50 days
d) 35 days
Answer:
b) 4 5 days

Question 21.
The cocoon is soaked in hot water in temperature for minutes.
a) 95°C – 97°C -10 -15 minute
b) 95°C – 97°C – 5 -10 minutes
c) 90°C – 95°C – 7 -10 minutes
d) 100°C – 105°C – 2 – 5 minutes
Answer:
a) 95°C – 97°C -10 -15 minute

Question 22.
The areas where a lot of beehives can be placed.
a) Honey culture
b) Apiculture
c) Apiaries
d) all the above
Answer:
c) apiaries

Question 23.
The nectar got from the flowers is converted into honey by the enzyme.
a) Invertase
b) Zymase
c) Lipase
d) None of the above
Answer:
a) Invertase

Question 24.
Find whether the following is true or false and find the correct sequence.
I) There is only one queen bee in a colony
II) Worker bees are around 5000 – 10000
III) The queen bee in its lifetime in 2 – 4 years lays 20 lakhs eggs.
IV) When the queen loses its fertility another worker bee becomes a queen by taking royal Jelly.
a) I – true, II – False, III – False, IV – true
b) I – true, II – False, III – true, IV – True
c) I – false, II – true, III – true, IV – true
d) I – false, II – true, III – false, IV – false
Answer:
a) I – true, II – false, III -false, IV – true.

Question 25.
How many days are needed for the worker bee to becoming mature done?
a) 15 days
b) 21 days
c) 20 days
d) 18 days
Answer:
b) 21 days

Question 26.
What is the life span of a worker bees?
a) 6 weeks
b) 5 weeks
c) 7 weeks
d) 3 weeks
Answer:
a) 6 weeks

Question 27.
What are drones?
a) a male bee from unfertilised egg
b) a female bee from fertilised egg
c) a queen bee from fertilised egg
d) a worker bee after eating royal jelly becomes a queen
Answer:
a) a male bee from unfertilised egg

Question 28.
Find the wrong pair?
a) Drone cell – Comb queen bee
b) King of honeycomb – Drone
c) Swarming – Worker bee flying with the queen bee
d) Male bee – After mating it will die
Answer:
a) Drone cell – Comb queen bee

Question 29.
Read the following statement and find the correct sequence.
I) The honeycomb is built from the abdominal secretion of a worker bee
II) The chamber of the honeycomb are hexagonal in shape
III) The young stages of honey bees accommodate the lower and central cells of the hive
IV) In Apis dorsata the brood of hive cells are similar in size and shape
a) I – false, II – false, III – true, IV – true
b) I – true, II – true, III – false, IV – false
c) I – true, II – true, III – true, IV – true
d) I – false, II – true, III – true, IV – false
Answer:
c) I – true, II – true, III – true, IV – true

Question 30.
Assertion A: The pure wax is white in colour.
Reason: B The pure wax contains carotenoids pigments.
a) Assertion A true Reason B true
b) Assertion A false, Reason B false
c) Assertion A true Reason B false
d) Assertion A false, Reason B true
Answer:
c) Assertion A true Reason B false.

Question 31.
Find the correct sequence in the following.
I) Bee wax is secreted by the abdomen of the worker bees.
II) The resinous chemical substance present in the wax is called propolis.
III) The pure wax is white in colour.
IV) The yellow of the wax is due to the carotenoid pigments.
a) I – true, II – true, III – true, IV – false
b) I – false, II – false, III – true, IV – true
c) I – true, II – false, III – true, IV – true
d) I – true, II – true, III – true, IV – true
Answer:
d) I – true, II – true, III – true, IV – true

Question 32.
Find whether the statement regarding Lac insect is true or false
I) Tachardia lacca produces lac.
II) The Lac insect is a parasite on host plant karanagalli, karuvelai
III) The female lac insects are small
IV) The female lac insects after fertilisation lays about 200 to 500 eggs
a) I – true, II – false, III – false, IV – true
b) I – true, II – true, III – true, IV – false
c) I – true, II – true, III – false, IV – true
d) I – true, II – false, III – true, IV – false
Answer:
c) I – true, II – true, III – false, IV – true

Question 33.
What is the ideal salinity for fish culture in brackish water?
a) 0.5-30ppt
b) 0.1-25ppt
c) 0.1-30ppt
d) 1-10ppt
Answer:
a) 0.5 – 30 ppt

Question 34.
Which one of the following is correct pair?
a) Exotic breed – cyprinus carpiols
b) Apiculture – Reeling
c) Seri culture – Propolis
d) Milch breed – Malvi
Answer:
a) Exotic breed – cyprinus Carpio

Question 35.
Name the exotic fishes of India.
a) Catlacatla
b) Lapeorohita
c) Cirrhina mirgala
d) Cyprinus carbeo
Answer:
d) Cyprinus carbeo

Question 36.
Name the vitamin found in fishoil?
a) A and E
b) A and D
c) A and C
d) A and K
Answer:
b) A and D

Question 37.
Ising glass is received from the part of the fish
a) Dried gills
b) Dried stomach
c) Dried air sacs
d) Dried liver
Answer:
c) Dried air sacs

Question 38.
What is the nutritive value of crustaceans?
a) Rich in glycogen protein with low-fat content
b) Rich in protein low in glycogen
c) Rich in glycogen low in fat content
d) Rich in protein and fat
Answer:
a) Rich in glycogen protein with low-fat content

Question 39.
These are freshwater prawns.
a) Penaeus indicus
b) Macrobrachium rosenbergi
c) Penaeus monodon
d) Metapenaeus
Answer:
b) Macrobrochium rosenbergi

Question 40.
What is the optimum temperature and PH for prawn culture in a hatching tank
a) 24°C – 30°C PH – 7 – 8
b) 20°C – 22°C PH -10 -12
c) 20°C – 23°C PH – 5 – 6
d) 19°C – 20°C PH – 9 -10
Answer:
a) 24°C – 30°C – PH – 7 – 8

Question 41.
Find the correct statement regarding the preparations of prawn form.
I) For algal growth, and for the subsequent stocking of prawns it is essential to drain off the water and sundry the bottom.
II) Lime should be applied to absorb excess C02 and to supply calcium which is required for moulting.
III) Fertilizers like rice, bran, poultry and cattle dung are used to increase the fertility of the soil.
IV) Preservation of prawns is done by peeling and deveining or by cooking and peeling
a) I – true, II – true, III – false, IV – false
b) I – false, II – true, III – true, IV – true
c) I – true, II – true, III – true, IV – true
d) I – true, II – false, III – true, IV – false
Answer:
c) I – true, II – true, III -true, IV – true

Question 42.
Where is pearl cultured in India for the first time?
a) Thoothukudi 1973
b) Visahapattinum 1974
c) Rameshwaram 1975
d) Kulchall973
Answer:
a) Thoothukudi 1973

Question 43.
Where are pearl oysters seen?
a) Kanyakumari coastal region a Bay of Kutch
b) Rameshwaram coastal area and Bay of Mannar
c) Nagapatinum coastal area and Thoothukudi
d) Visahapatinum coastal area and Chennai
Answer:
a) Kanyakumari coastal region a Bay of Kutch

Question 44.
The pearl oysters belongs to ‘L’ genus produce Quality pearls.
a) Gastropoda
b) Pinctata
c) Pelecypoda
d) Cephalopoda
Answer:
b) Pinctata

Question 45.
……………………….. ulturing pearl in freshwater.
a) Lamellidens
b) Mytilus
c) Loligo
d) Dentalium
Answer:
a) Lamellidens

Question 46.
The marine oysters are composed of
a) Calcium carbonate
b) Sodium carbonate
c) Potassium carbonate
d) Magnesium carbonate
Answer:
a) Calcium carbonate

Question 47.
The process of killing the silkworm cocoons is called
a) Reeling
b) Stifling
c) Spinning
d) rearing
Answer:
b) Stifling

Question 48.
Assertion A: The pearl oysters got from the sea are valuable
Reason B: The pearl oysters got from freshwater is not valuable
a) Assertion A true, B false
b) Assertion A and B reason all true
c) Assertion A false, Reason B true
d) Assertion A and Bare false
Answer:
b) Assertion A and B reason all true

Question 49.
What is the name of the breed that produces mule?
a) Outbreeding
b) Crossbreeding
c) Interspecific hybridization
d) Outbreeding
Answer:
c) Interspecific hybridization

Question 50.
Assertion X: 6 – 8 eggs can be produced by induction in an artificial method
Reason Y: The embryos at 8 – 32 celled stages are transferred to a surrogate mother.
a) Assertion x false y true
b) Assertion X true, Y false
c) Assertion X false, Y false
d) Assertion X and Y are true
Answer:
d) Assertion X and Y are true

Question 51.
Which of the cattle breed yields more milk than what they eat?
a) Vechur
b) Kankeyem
c) Gir
d) Ongole
Answer:
a) Vechur

Question 52.
Which of the following is not a milch breed?
a) Sindhi
b) Malvi
c) Jersey
d) Gir
Answer:
b) Malvi

Question 53.
Which of the following belongs to America?
a) Silkie
b) White Plymouth rock
c) Chittagong
d) Aseel
Answer:
b) White Plymouth rock

Question 54.
Name the poultry which is noted for its pugnacity?
a) Leghorn
b) Silkie
c) Brahma
d) Aseel
Answer:
d) Aseel

Question 55.
Find the odd one out
a) Leghorn – Italy
b) Chittagong – good egg yielder
c) White Plymouth rock – American breed
d) Aseel-ornamental breed
Answer:
d) Aseel – ornamental breed

Question 56.
Which among the following is a wild duck?
a) Syhlet
b) Muscori
c) Pekin
d) Mallard
Answer:
d) Mallard

Question 57.
Find the wrong statement about Duck.
a) The body is covered with oily feathers.
b) The fat layer beneath their skin prevents it from getting wet
c) They lay eggs at mid-day
d) The ducks feed on rice bran kitchen wastes and snails
Answer:
c) They lay eggs at midday

(2 marks)

II. Very Short Answer

Question 1.
What is Economic Zoology?
Answer:
Economic zoology is a branch of science that deals with economically useful animals. It involves the study of the application of animals for human welfare.

Question 2.
How are animals classified on the basis of their economic importance?
Answer:

• Animals for food and food products.
• Economically beneficial animals.
• Animals of aesthetic importance.
• Animals for scientific research.

Question 3.
Name the endemic earthworms of India.
Answer:

1. Periy ony x excavatus
2. Lampito Mauritius
3. Octo chactona serrata

Question 4.
Name the exotic species of an earthworm?
Answer:

• Eiseniafetida,
• Eudrilus eugeniae

Question 5.
Why are earthworms called ‘friends of farmers’?
Answer:
Earthworms play a vital role in maintaining soil fertility. Hence, they are called ‘friends of farmers’.

Question 6.
What decides the economic success of the industries?
Answer:

• It depends on the animals and their products.
• It depends on the proper production management and development of the next generation of farm animals.

Question 7.
What is meant by vermiculture?
Answer:
It is the process of using earthworm to decompose organic food waste into a nutrient-rich material capable of supplying necessary nutrients which help to sustain plant growth.

Question 8.
What is meant by vermicast?
Answer:
The organic matter of soil is decomposed by earthworm and becomes nutritious rich manure for plant growth.

Question 9.
What is meant by vermicompost?
Answer:
Vermicompost is composed of vermicast which contains nutrients plant growth promoters and organic matters.

Question 10.
What is meant by vermitech?
Answer:
The application of earthworm in the technology of composting and bioremediation of soil and other activities is called vermitech.

Question 11.
What are the pests of earthworms?
Answer:
Ants, springtails, centipedes, slugs, mites, certain beetle larvae, birds, rats, snakes, mice, toads and other insects or animals which feed on worms.

Question 12.
What are the special characters of vermicompost?
Answer:

• Aeration
• draining of water
• retains water.

Question 13.
What is meant by vermiwash?
Answer:

• Vermi wash is a liquid collected after the passage of water through a coloumn of vermibed.
• It is useful as foliar spray to enhance plant growth and field.

Question 14.
What is sericulture?
Answer:
Sericulture is an agro-based industry which denotes commercial production of silk through silkworm rearing.

Question 15.
What is meant by sericulture?
Answer:
Sericulture denotes commercial production of silk through silk worm rearing.

Question 16.
What is meant by moriculture?
Answer:
The cultivation of mulberry plant which is used as a food for silk worm is called moriculture.

Question 17.
Which is the suitable period for mulberry cultivation?
Answer:
June, July, November, and December

Question 18.
What are the stages involved in rearing process of silk worm?
Answer:
Disinfection of rearing house Incubation of eggs Brushing, young larval rearing Late age larval rearing.

Question 19.
What is meant by stifling?
Answer:
The process of killing the cocoon is called stifling.

Question 20.
What is meant by reeling?
Answer:
The process of removing the threads from the killed cocoon is called reeling.

Question 21.
What is cooking?
Answer:
The process of soaking cocoons in hot water (95° – 97°) for 10 – 15 minutes to soften the gum that binds the silk threads together is called cooking.

Question 22.
What are Uzi files?
Answer:
These files which can attack silkworm.

Question 23.
What is meant by cooking?
Answer:
The cocoons are soaked in hot water at 95° – 97°c for 10 -15 minutes to soften the gum that binds, the silk threads together are called cooking.

Question 24.
What is spun silk?
Answer:
The silk produced from silk wastes used for producing spun silk.

Question 25.
What are apiaries?
Answer:
They are areas where a lot of beehives can be placed.

Question 26.
Name the bees used for Apiculture.
Answer:

• Apis dorsata – Rock bee
• Apis florea – Little bee
• Apis indica – Indian bee
• Apismellifera – European bee
• Apis adamsoni – African bee

Question 27.
Name the types of beehives which are in practice in India?
Answer:

• Langstroth
• Newton

Question 28.
What is meant by swarming?
Answer:
The mass emergence of larvae of Lacinsect from the egg in search of a host plant is called swarming.

Question 29.
What is meant by nuptial flight?
Answer:
A unique flight that takes place by the queen bee followed by several drones is called “nuptial flight”.

Question 30.
Which is called as king of the colony? Why is called so?
Answer:
The king of colony is drone hence the sole duty of the drone is to fertilize the vergin queen.

Question 31.
Name the sugar component present in the honey?
Answer:
levulose, dextrose maltose.

Question 32.
What are the uses of honey?
Answer:

• It is used as an antiseptic
• Laxative
• Sedative
• It is used in the preparation of cakes bread and biscuits.

Question 33.
What is meant by Lac culture?
Answer:
The culture of lac insect using techniques for the procurement of Lac on large scale is known as Lac culture.

Question 34.
Name the host plants on which Lac insects live?
Answer:
Karanagalli – Acacia catechu Karuvelai – Acacia nilotica Kumbadiri – Schleichera oleosa.

Question 35.
What is meant by hyper parasitism?
Answer:

• Hyper parasitism is a condition in which a secondary parasite develops within a previously existing parasite.
• The caterpillars feed upon lac insects showing hyper – parasitism.

Question 36.
What is meant by inoculation?
Answer:
The process of introducing lac insects to the host plant is called inoculation.

Question 37.
What is meant by Harvesting?
Answer:
The collection of Lac from the host plant is known as harvesting.

Question 38.
What is meant by ‘Arilac’?
Answer:
The Immature lac insects produce a lac which is called ‘arilac’.

Question 39.
What is meant by sticklac?
Answer:
Lac cut from the host plant is called ‘stick lac’.

Question 40.
What is seed Lac?
Answer:
The Lac scraped collected grounded and the dust particles are removed to produce a lac called seedlac.

Question 41.
What is meant by Shellac?
Answer:
The seedlac is sundried and then melted to produce “Shellac”.

Question 42.
What is meant by aqua ponies?
Answer:
Aquaponics is a technique which is a combination of aquaculture and growing plants in non – soil media and nutrient-laden water.

Question 43.
What are the organisms farming through aqual culture?
Answer:
Fish molluscs crustaceans and aquatic plants are farming through aquaculture.

Question 44.
How aquaculture is classified on the basis of it source?
Answer:

• Freshwater aquaculture
• Brackish water aquaculture
• Marine water aquaculture.

Question 45.
What is meant by Brackish water culture?
Answer:
Culturing of animals in the water having salinity range 0.5 – 30ppt are called brackish water cultures.

Question 46.
Name the fishes cultured through brackish water culture?
Answer:
Milkfish, Sea bass, Grey mullet Kari meen.

Question 47.
What is meant by metahaline culture?
Answer:
Culturing of animals in the salinity ranges from 36 – 40o% is called metahaline culture (eg) Artemia salina.

Question 48.
What are the organisms rearing through aquaculture?
Answer:

1. Molluscs
2. Aquatic plants
3. Crustaceans

Question 49.
Give notes on fishes of brackish water?
Answer:
Brackish water fishes spend most of its life in river mouths backwaters mangrove swamps and coastal lagoons.

Question 50.
What is meant by mariculture?
Answer:
Culturing of animals in the water salinity ranges from 35- 35% is called mariculture.

Question 51.
Give short notes on Artemia salina?
Answer:
It is a metahaline organism. It lives in high saline waters because of its high osmoregulatory capacity.

Question 52.
What is meant by composite fish culture?
Answer:
Few selected fishes belonging to different species are stocked together in proper proportion in the pond is called composite culture.

Question 53.
What are the organisms cultured through composite fish culture?
Answer:

• Catla Catla
• Labeo rohita
• Cirrhina mirgala.

Question 54.
What is meant by exotic fish culture?
Answer:
The fishes imported in to a country for fish culture are called exotic fishes and such fish culture is known as exotic fish culture.

Question 55.
Name the exotic fishes cultured in India?
Answer:

• Cyprinus carpio
• Oreochromis mossambicus.

Question 56.
What is meant by fish meal?
Answer:
Fish meal is prepared from fish waste after extracting oil from the fish.

Question 57.
What is meant by Ising glass?
Answer:

• Ising glass is high-grade collagen produced from dried air bladder.
• It is used for clarification of wine beer and vinegar.

Question 58.
What is meant by outbreeding?
Answer:
It is the breeding of unrelated animals. They do not have common ancestry for 4-6 generations.

Question 59.
What is the use of outbreeding?
Answer:
Outbreeding helps to produce hybrids with superior qualities and helps to create new breeds. New and favourable genes can be introduced into a population through outbreeding.

Question 60.
What is meant by outcrossing?
Answer:
It is the breeding between unrelated animals of the same breed but having no common ancertry.

Question 61.
What is meant by artificial insemination?
Answer:
Artificial insemination is a technique in which the semen collected from the male is injected to the reproductive tract of the selected female.

Question 62.
What is meant by recovery period?
Answer:
Nucleated oysters are attached with floating rafts suspended into a depth of 2 to 3 metres for about 6 to 7 days is called the recovery period.

Question 63.
What is the composition of pearl?
Answer:

• Water-2-4%
• Calcium carbonate-90%
• Organic matter-3.5-5.9%
• residue-0.1-0.8%

Question 64.
Name the species of prawn?
Answer:
Penaues indicus, Penaeus monodon, Metapenaeus dobsoni, Macrobrachium rosenbergil.

Question 65.
Where are pearl oysters cultured?
Answer:
Kanyakumari Bay of Kutch.

Question 66.
What is meant by Linga pearl or best quality pearl?
Answer:
The pearl oysters in habit the ridges of rock-forming extensive pearl banks. These pearl beds produce the best quality of pearl or Linga pearl.

Question 67.
What are the types of cultivable fish?
Answer:

• Indigenous or native freshwater fish. (cg) Catla, Labeo
• Saltwater fishes acclimatized for freshwater.
• Exotic fishes or imported from other countries. (eg) Common Carps.

Question 68.
What is Hapa?
Answer:
Hatching hapas are rectangular through shaped tanks made up of mosquito net cloth supported by bampoo poles and fixed in the river.

Question 69.
What are the advantages of composite fish farming?
Answer:

•  All available niches are fully utilized.
• Compatible species do not harm each other.
• No competition among different species.

Question 70.
What is meant by animal husbandry?
Answer:
Animal husbandry is the practise of breeding and raising livestock cattle like cows, buffaloes goats and birds that are useful to human beings.

Question 71.
What is meant by breed?
Answer:
A group of animals related by descent and with similar characters like general appearance features size etc as said to belong to a breed.

Question 72.
How can we classify cattle on the basis of their utility?
Answer:

1. Milch breeds
2. Draught purpose breeds
3. Dual-purpose breeds.

Question 73.
What are characteristic features of healthy cattle?
Answer:

• They appear bright
• Alert
• Active
• Shiny coat.

Question 74.
What are the characteristic features of unhealthy cattle?
Answer:

• They appear dull
• Restless
• Change posture frequently with a drop in milk yield.

Question 75.
Name the important cattle disease?
Answer:

• Rinder pest
• Cowpox
• Anthrax
• hemorrhagic fever.

Question 76.
What is meant by poultry?
Answer:
It is the rearing and propagation of chicken ducks turkeys geese quail and guinea fowls.

Question 77.
What are the types of chicken breeds based on their utility?
Answer:

• They are egg layers
• Broiler type
• Dual type
• Games and
• ornamental types.

Question 78.
Name the native ducks.
Answer:

• Indian Runner
• Syhletmeta.

Question 79.
Name the exotic ducks.
Answer:

• Muscari
• Pekin
• Aylesbury
• Campbell

Question 80.
What are the three stages of sericulture?
Answer:

1. Cultivation of food plants for the silkworm.
2. rearing of silkworm.
3. reeling and spinning of silk.

Question 81.
What is meant by apiculture?
Answer:
Care and management of honey bees on a commercial scale for the production of honey is called apiculture.

Question 82.
What is the importance of aquaponics?
Answer:
It maintains the ecosystem balance by recycling the waste and excretory products produced by the fish.

Question 83.
What is meant by aquaponics?
Answer:
Aquaponics is a technique which is a combination of aquaculture and growing plants in non-soil media and nutrient-laden water.

Question 84.
Based on the water resources where are aquatic organisms cultured? Give examples.
Answer:

1. Freshwater culture
2. Brackish water culture, Marine culture, Cultured organism, Fishes, Prawns, Crabs and oysters.

Question 85.
What are the objectives of animal breeding?
Answer:

• To improve growth rate
• enhancing the production of milk meat egg etc.
• Increasing the quality of the animal products
• Improved resistance to disease.
• Increased reproductive rate.

3 marks

III. Short answers

Question 1.
What is meant by vermiculture?
Answer:
It is the process of using earthworm to decompose organic food waste into a nutrient-rich material capable of supplying necessary nutrients which help to sustain plant growth.

Question 2.
What is meant by worm casting?
Answer:
The worm castings are pure worm waste and nutrient-rich organic soil and composed of castings, bits of bedding, and other organic matter.

Question 3.
Why earthworms are called as ‘Farmers of friends’
Answer:

• They support bacteria fungi which are essential for sustaining healthy soil.
• The breakdown of organic matter by the activity of the earthworms.
• It increases porosity aeration, drainage of the soil.

Question 4.
What are the three main components of sericulture?
Answer:

1. Cultivation of food plants for the silkworms.
2. Rearing of silkworms.
3. Reeling and spinning of silk.

Question 5.
Name the predators of earthworms?
Answer:

• Ants,
• centipedes,
• Slugs,
• Birds,
• Rats,
• Snakes.

Question 6.
Name the honey bees used in apiculture.
Answer:

• Apis dorsate,
• Apis florea
• Apis indica
• Apis mellifera
• Apisadamsoni

Question 7.
Whatisprobolis?
Answer:
The wax is masticated and mixed with the secretions of the cephalic glands to convert it into a plastic resinous substance called probolis.

Question 8.
What are the uses of silk?
Answer:
Uses of Silk:-
1. Silk fibers are utilized in preparing silk clothes. Silk fibers are now combined with other natural or synthetic fibers to manufacture clothes like Teri-Silk, Cot-Silk etc. Silk is dyed and printed to prepare ornamented fabrics. They are generally made from Eri-silk or spun silk.

2. Silk is used in industries and for military purposes.

3. It is used in the manufacture of fishing fibers, parachutes, cartridge bags, insulation coils for telephone, wireless receivers, tyres of racing cars, filter fibres, medical dressings, and suture materials.

Question 9.
Describe the structure of Beehive?
Answer:

• The house of honey bees is a beehive.
• The hive consists of hexagonal cells made up of wax secreted by the abdomen of a worker bee.

• These hives are found hanging vertically from the rocks. building or branches of trees.
• The young stages of honey bee accommodate the lower and central cells of the hive.
• In the rock bees hives there are separate cells for queens, worker and drones.

Question 10.
Explain the structure of a beehive?
Answer:
Structure of a Bee Hive. The house of honey bees is termed a beehive or comb. The hive consists of hexagonal cells made up of wax secreted by the abdomen of worker bees arranged in opposite rows on a common base. These hives are found hanging vertically from the rocks, buildings or branches of trees. The young stages of honey bees accommodate the lower and central cells of the hive called the brood cells.

In Apis dorsata, the brood cells are similar in size and shape but in other species, brood cells are of three types viz., queen cell for queens, worker cell for workers, and drone cells for drones. The cells are intended for the storage of honey and pollen in the upper portion of the comb whereas the lower portions are for brood rearing.

Question 11.
What is meant by inbreeding? What are its effects?
Answer:
Breeding between animals of the same breed for 4 – 6 generations is called inbreeding.
Effects:

1. It increases homozygosity.
2. Exposes the harmful recessive genes.
3. Reduces fertility.
4. It produces inbreeding depression.

Question 12.
How animals are classified based on their economic importance.
Answer:

• Animals for food and food products.
• Economically beneficial animals.
• Animals of aesthetic importance.
• Animals for scientific research.

Question 13.
Give an account of earthworm based on their habitat.
Answer:
First group:

• The humus formers dwell on the surface and feed on organic matter.
• They are darker in colour.
• These worms are used for vermicomposting.

Second group:
The humus feeders are burrowing worms that are useful in making the soil porous and mixing and distributing humus throughout the soil.

Question 14.
What are the uses of honey wax?
Answer:

• It is used for making candles.
• It is used for making waterproofing materials.
• It is used for making home appliances polishes for leather.
• It is used in pharmaceutical industries.

Question 15.
What is meant by Hyper parasitism?
Answer:
A condition in which a secondary parasite develops within a previously existing parasite.

Question 16.
What are the economic importance of Lac?
Answer:

• It is used as sealing wax.
• It is used as a good insulator.
• It is used in preparations of shoe and leather polishes.
• It is a protective coating of wood.
• It is used in preparation of plastic moulded articles.
• It is used as filling material for gold ornament.

Question 17.
Name the breeds of cattle?
Answer:

• Milch breeds – Sindhi Jersey
• Draught breeds – KangeyamMalvi
• Dual-purpose breeds – Ongole Hariana

Question 18.
What is meant by Milch breed?
Answer:
They are high milk yielders with extended lactation. (eg) Sindhi, brown swiss.

Question 19.
What is Dual purpose?
Answer:
Cows are meant for yielding more milk and bullocks are used for better drought purpose, (eg) Ongole Hariana

Question 20.
What is draught purpose breeds?
Answer:
Bullocks are good for draught purposes (eg) Malvi.

Question 21.
What are the characteristic features of healthy cattle?
Answer:
A healthy animal eats drinks and sleeps well regularly.
Healthy cattle appear bright.
Alert and active in their movement with a shiny coat.

Question 22.
What are the external factors affecting fish culture?
Answer:

1. Temperature,
2. Light,
3. Rain,
4. Flood,
5. Water current,
6. Turbidity of water,
7. pH

Question 23.
What is Aquaponics?
Answer:
Aquaponics is a technique which is a combination of aquaculture (growing fish)’ and hydroponics (growing plants in non-soil media and nutrient-laden water).

Question 24.
Name the species of prawn.
Answer:

• Penaeus indicus,
• Penaeus monodon,
• Metapenaeus dobson,
• Macrobrachium rosenbergii.

Question 25.
What are the three types of aquaculture on the basis of the source?
Answer:
On the basis of source, aquaculture can be classified into three categories. They are

1. Freshwater aquaculture
2. Brackish water aquaculture
3. Marine water aquaculture.

Question 26.
What are the benefits of poultry farming?
Answer:

• It does not require high capital for the construction and maintenance of poultry farming.
• It does not require a big space.
• It ensures the high return on investment.
• It provides fresh and nutritious food and has a huge global demand.
• It provides employment opportunities for the people.

Question 27.
What are the uses of dairy products?
Answer:

• Milk is a rich source of vitamin A, B₂, B₁
• It is a complete food for infants.
• Dairy products such as yoghurt cheese butter ice cream condensed milk, milk powder are produced from milk.

Question 28.
What is the importance of meat?
Answer:

• Meat is rich in protein.
• It also contains minerals like iron zinc vitamins and selenium.

Question 29.
What is Mariculture?
Answer:
Culturing of animals in the water salinity ranges from 30 – 35% is called Mariculture. Some fishes like Chanos sp, Mugil cephalus are cultured here.

Question 30.
What are poultry diseases?
Answer:
Ranikhet, Coccidiosis, Fowl pox.

5 Marks

IV. Give Detailed Answers

Question 1.
How are vermicompost produced?
Answer:
Types of Movements:

• Vermicompost is the compost produced by the action of earthworm in association with all other organisms in the compost unit.
• Vermicompost bed may be selected on upland or an elevated level.
• We have to construct a cement pit of 3 x 2 x 1m size over the ground surface using bricks.
• The vermibed should not be exposed to direct sunlight.
• The first layer of vermibed contains gravel at about 5 cm in height followed by coarses and to a thickness of 3.5 cm which will facilitate the draniage of excess water.
• The unit can now be loaded with digested biomass or animal dung.
• Earthworms such as periyonyx excavatus Eisenia fetida or Eudrilus eugeniae are introduced on the top.
• Earthworms release their castings on the surface.
• Vermiwash is a liquid collected after the passage of water through a column of vermibed. It is useful as a foliar spray to enhance plant growth.

Question 2.
Describe the life cycle of bombyx mon?
Answer:

• This moth is unisexual.
• Just after emergence male moth copulates with females for 2-3 hours.
• Just after copulation female starts laying about 400-500 eggs.
• The eggs after ten days of incubation hatch into larva called a caterpillar.
• The newly hatched caterpillar is about 3mm in length and is pale yellowish-white colour.
• The mandibulate type of mouthparts adapted to feed easily on the mulberry leaves.

• After 1st, 2nd, 3rd and 4th moulting caterpillars get transformed into 2nd, 3rd, 4th and 5th instars respectively.
• It develops salivary glands, stops feeding and undergoes pupation.
• The cafter pillars stop feeding and moves towards the comer among the leaves and secrete a sticky fluid through their silk gland.
• The secreted fluid comes out through spinnerret which hardens on exposure to air and is wrapped around the body of cater pillar in the forms of a covering called a cocoon.
• The length of continous thread secreted a caterpillar for the formation of cocoon is about 1000 -1200 metres.
• The pupal period lasts for 10-12 days and the pupae cut through the cocoon and emerge into adult moth.
• In larvel stages the larvae moults for 3 or 4 times or 5 times and become a matured moth.

Question 3.
What are the uses of vermicompost?
Answer:

• Vermicompost is rich in essential plant nutrients.
• It improves soil structure texture aeration and water holding capacity and prevents soil erosion.
• Vermicompost is rich in nutrients and an eco-friendly amendment soil for farming and terrace gardening.
• It enhances seed germination and ensures good plant growth.

Question 4.
What are the reasons for culturing carps in India?
Answer:
Major carps have proved to be best suited for culture in India because the carps

1. Feed on zooplankton and phytoplankton, decaying weeds, debris, and other aquatic plants.
2. They can survive in turbid water with slightly higher temperatures.
3. Can tolerate O₂ variations in water.
4. Can be transported from one place to another easily.
5. They are highly nutritive and palatable.

Question 5.
What are the uses of silk?
Answer:

• Silk fibres are utilized in preparing silk cloths.
• Silk fibres are combined with natural or synthetic fibres to manufacture Teri – silk and cot silk.
• Silk is dyed and printed to prepare ornamental fabrics.
• Silk is used in industries and for military purposes.
• It is used in the manufacturing of fishing fibres, parachutes insulation coils for telephones.
• They are used in the preparation of tyre of racing cars, filter fibres in medical dressings and as suture materials.

Question 6.
Name the pests and diseases of the silkworm.
Answer:
1. Predators:
They feed on silkworms.

• Birds,
• ants,
• crows,
• kites,
• rats.

2. Diseases:

• Pebrin – It is a disease caused by protozoa Nosema bombycis.
• Flacherie – It occurs in the mature larvae caused by bacteria like streptococcus and staphylococcus.
• Grasserie – It is aviral disease caused by Bombyx mori nuclear polyhedrosis virus.
• White Muscardine – It is caused by fungus Beauveria bassiana.

Question 7.
Describe the social organziation of honey bee.
Answer:

• In honey bee a highly organized division of labour is found.
• There are three type of honey bees seen in the colony.
• There are one queen 10000 – 30000 workers and few hundred drones in a colony.

Queen bee:

• It feeds on royal Jelly.
• It is only function is to lay eggs throughout its life span.
• During breeding season in winter, a unique flight takes place by the queen bee followed by several drones is called nuptial flight.
• After mating the queen bee lays about 15 lakh eggs in two to four years.

Worker bee:

• These are sterile females.
• Worker bee lives in a worker well and it takes, about 21 days to develop from the egg to adult, and its life span is about six weeks.

Works:

• It secretes royal Jelly.
• Prepares bee – bread to feed the larvae.
• Takes care of the queen and drones.
• Secretes bee wax.
• In last three weeks she searches and gathers the pollen nectar.

Drones:

• The drone develops from an unfertilized egg.
• It lives in a chamber called a drone cell.
• The only duty of the drone is to fertilize the queen and it is called as the king of the colony.

Question 8.
Describe the structure of the Langstroth beehive?
Answer:

• Stand – It is a basal part of the hive and are adjusted to make a slope for rainwater to drain.
• Bottom board – It is situated above the stand. It has two gates one gate is an entrance the other acts as an exit.
• Brood chamber – It is an important part of the hive. It is provided with 5 to 10 frames arranged one above the other through which the workers can easily pass.
• The frame is composed of wax – sheet which is held in a vertical position up by a couple of wires.
• It is strong that can be used repeatedly.
• Super – It is a chamber without cover and base. It is provided with many frames to provide additional space for expansion of the hive.
• Inner cover – It is a wooden piece used for covering the super with many holes for proper ventilation.
• Top cover – It is meant for protecting the colonies from rains. It is covered with a sheet which is plain and sloping.

Question 9.
Give an account of equipments of beehives and its uses.
Answer:

• Queen Excluder – It is utilized to prevent the entry of queen bee from the brood chamber into the super chamber.
• Comb foundation – It is a sheet of bee wax.
• Bee gloves – They are used by keepers for protecting their hands.
• Bee veil – It is a device to protect the beekeeper from a bee sting.
• Smoker – It is used to scare the bees during honey collecting.
• Hive Tool – It helps in scraping excess propolis or wax.
• Un capping knife – It helps in removing the cap from the combs.
• Bee brush – It is used to brush off bees from honeycombs.
• Queen introducing cage – It is made of wire nets used for keeping the queen for 24 hours with worker bees.
• Feeder – It is a basin with sugar syrub covered by grass to feed the bees during the drought season.
• Honey extractor – This spins the combs rapidly to extract honey.
• Hive entrance guard – It is a device which prevents the escape of the queen during the warming season.

Question 10.
Describe the process of rearing silkworms?
Answer:

• A typical rearing house 6 m x 4m x 3.5m is constructed on an elevated place under shade to accommodate 100 dfls.
• The windows and ventilators should be covered with a nylon net to restrict the entry of uziflies and other insects.
• The selected healthy silk moths are allowed to mate for 4 hours.
• The female moth is kept in a dark plastic bed it lays about 400 eggs in 24 hours.
• The small larvae hatch between 7 – 10 days.
• The larvae are kept in trays at a temperature of about 20°C-25°C.
• As the larvae grow they are transferred to fresh leaves on clean trays.
• Their maturity is achieved in about 45 days.
• At this stage the salivary glands start secreting silk to spin cocoons.

Question 11.
What is meant by aquaponics? Describe its methods?
Answer:
1. Deepwater culture – Aquaponics is a technique which is a combination of aquaculture and growing plants in non – soil media.

• It is a raft-based method.

• In this method, the raft floats in water plants are kept in the holes of the raft and the root floats in water. Fast-growing plants are cultivated.

2. Media-based method – It involves growing plants in inert planting media likely pellets or shales.
This method is applicable for home and hobby scale system. Large number of fruiting plants leafy green plants herbs can be cultivated.

3. Nutrient film technique – It involves the passage of nutrient-rich water through a narrow trough or pvc pipe.
Plants are kept in the holes of the pipe to allow the roots to be in free contact with the water stream.

4. Aquavertica or vertical aquaponics – Plants are stacked in top of each other in tower systems.
This method is suitable for growing leafy green, strawberries and crops that do not need supporting solid substratum to grow.

Question 12.
Describe the structure of honey bee hive?
Answer:

• The house of honey bee is termedas bee hive or comb.
• The hive consists of hexagonal cells made up of wax secreted by the abdomen of worker bee arranged in opposite rows on a common base.
• These hives are found hanging vertically from the rocks building or branches of trees.
• The young stages of honey bees accomodate the lower and central cells of the hive called the brood cells.
• There are separate cells for queen. Drones and workers.
• In the upper portion of the comb honey and pollen are stored.
• In the lower portion are for brood rearing.

Question 13.
What is Natural breeding of fishes?
Answer:
Natural breeding (Bundh breeding): These are special types of ponds where natural riverine conditions or any natural water resources are managed for the breeding of culturable fishes. These bundhs are constructed in large low-lying areas that can accommodate large quantity of rainwater. The shallow area of such bundhs is used as a spawning ground.

Question 14.
What are the characteristic features of cultivable fishes.
Answer:

• Fishes should have high growth rate in short period for culture.
• They should accept a supplementary diet.
• They should be hardly enough to resist some common diseases and infection of parasites.
• Fishes proposed for polyculture should be able to live together without interferring or attaching other
  fishes.
• They should have high conversion efficiency so that they can effectively utilize the food.

Question 15.
Why carps have proved to be best suited for culture in India?
Answer:

• Feed on zooplanktons and phytoplanktons decaying weeds debris and other aquatic plants.
• They can survive in turbid water with slightly higher temperatures.
• Can tolerate O₂ variations in water.
• Can be transported from one place to another easily.
• They are highly nutritive and palatable.

Question 16.
Give an account of induced breeding.
Answer:

• To improve the quality of fish seed by the artificial method of fertilization is developed.
• The gonadotrophin (FSH+ LH) secreted by the pituitary gland influences the maturation of gonads and spawning in fishes.
• The pituitary gland is removed from a healthy mature fish.
• The pituitary extract is prepared by homogenizing in 0.3% saline and centrifuged for 15 minutes at 8000rpm.
• The supernatant is injected at the base of the caudal fin.
• Male and Female fishes start to releasing gametes and are fertilized.

Question 17.
What are the types of prawn fishery?
Answer:

1. Shallow water prawn fishery – This is located on the west coast restricted to shallow waters.
2. Estuaries prawn fishery – In the backwater areas of the western coast, Ennur pulicat chilka lake and Estuaries of Ganga and Brahmaputra culture is done.
3. Freshwater prawn fishery – Prawns are caught from the rivers and lakes throughout India.
4. Marine prawn fishery – Prawn belongs to the family, penaeidae are caught along the Indian coast.

Question 18.
Give an account of the culture of freshwater prawns?
Answer:

• Macrobrachium rosenbergii is seen in rivers fields and low – saline estuaries.
• For fertilization, one pair of prawn are kept in a separate tank.
• After mating the eggs are laid.
• Temperature 24°C – 30°C and PH 7-8 should be maintained in the hatching tank.
• The hatched larvae are supplied with artificial feed.
• Young ones 5cm length can be reared in fresh or slightly brackish water ponds and harvesting of prawns can be done twice a year.

Question 19.
What are the methods of animal breeding?
Answer:
Methods of Animal breeding:
There are two methods of animal breeding, namely inbreeding and outbreeding:

1. Inbreeding: Breeding between animals of the same breed for 4-6 generations is called inbreeding. Inbreeding increases homozygosity and exposes the harmful recessive genes.

Continuous inbreeding reduces fertility and even productivity, resulting in “inbreeding depression”. This can be avoided by breeding selected animals of the breeding population and they should be mated with superior animals of the same breed but unrelated to the breeding population. It helps to restore fertility and yield.

2. Outbreeding: The breeding between unrelated animals is called outbreeding. Individuals produced do not have common ancestors for 4-6 generations.

Outbreeding helps to produce new and favourable traits, to produce hybrids, with superior qualities, and helps to create new breeds. New and favourable genes can be introduced into a population through outbreeding

Question 20.
What are the types of cultivable fish Types of cultivable fishes?
Answer:
Types of Cultivable fishes:

• Indigenous / Native freshwater fishes, (eg) Major Carps Catla Labeo Clarias.
• Saltwater fishes acclimatized for freshwater. (eg)Chanos, Mullet
• Exotic fishes. Imported from other countries, (eg) Common Carps.

Characteristic features of Carps:

• Feed on Zooplanktons and phytoplanktons decaying weeds debris and other aquatic plants.
• They can survive in turbid water with slightly higher temperatures.
• Can tolerate 0₂ variations in water.
• Can be transported from one place to other.
• They are highly nutritive and palatable easily

Question 21.
Give an account of the management of fish farms?
Answer:
To culture fish one should have an idea about different stages of fish culture such as topographic situation quality source physical-chemical and biological factors of water.
Stages of fish farming:
Breeding Pond:
The first step in fish culture is the breeding of fishes therefore for proper breeding special types of ponds are prepared called breeding ponds. These ponds are prepared near the rivers of natural water resources.
a) Natural breeding:
These bundhs are constructed in large low-lying areas that can accommodate a large quantity of rainwater.
b) Induced breeding:

• This involves the removal of ova and sperm from female and male by artificial mechanical process and the eggs are fertilized.
• The fertilized eggs are removed from the spawning place and kept in hatching hapas. Fish seeds: The fish seed is collected from breeding ponds and transferred to the hatching pits.

3. Hatching Pit:
The fertilized eggs are kept in hatching pits. The hatching pits should be nearer to the breeding grounds should be smaller in size with good quality water.
There are two types of hatching pits:

1. Hatcheries: These are small-sized ponds in which unfertilized eggs are transferred and hatching happens.
2. Hatching hapas: These are rectangular trough-shaped tanks made up of mosquito net cloth supported by bamboo poles and fixed in the river.

4. Nursery Pond:
The newly hatched fries are transported from the hatching happa to nursery ponds where they grow into fingerlings.

5. Rearing Pond:
This pond is long and narrow and this pond should be free from toxicants and predators. The fingerlings are transferred to the stocking ponds.

6. Stocking Ponds:

• This pond should be devoid of weeds and predatory fishes.
• Proper organic manuring should be done to the production with cow dung.

7. Harvesting:

• Well-grown fishes are taken out for marketing is harvesting.
• Small-sized fishes are again released into the stocking ponds for further growth.
• The harvested fishes are preserved and then marketed.

Question 22.
a) What is meant by composite fish farming?
b) What are the significance?
c) What are the fishes cultured through composite fish farming.
Answer:
a. Composite fish farming: Few selected fishes belonging to different species are stocked together in proper proportion in a pond is called composite fish farming.

b. Merits :

• All available niches are fully utilized.
• Compatible species do not harm each other.
• No competition among different species is found.

c. Fishes that are cultured :

• Catla Catla
• Labeo rohita
• Cirrhinus mrigala

Question 23.
Give an account of the economic importance of fish.
Answer:
1. Fishes form a rich source of protein food the sardines, mackerel tuna herrings have high amino acid concentrations.
2. These fishes have histidine and omega falty acids.
3. Minerals such as calcium magnesium phosphorus potassium and copper and present.
a) Fish Oil:

• It is an important fish product it is derived from fish liver and from the fish body.
• This is rich in vitamin A and O and iodine.
• It is used in the manufacture of laundry soap paints and cosmetics.

b) Fish Meal:

• It is prepared from fish waste after extracting oil from the fish.
• These dried wastes are used to prepare food for pig, poultry and cattle.
• The wastes obtained during the preparation of fish meal are used as manure.

c) Ising glass:

• It is high-grade collagen produced from dried air bladder of cat fish and carps.
• It is used for clarification of wine beer and vinegar.

Question 24.
Give notes on
a) Pearl Culture
b) Formation of pearl.
Answer:
a) Pearl Culture:

• Pearl is a white shining globular concretion found within the shell of an oyster.
• In India it was cultured for the first time in 1973 at Thoothukudi.
• High-quality pearls are obtained from Genus Pinctada that can be cultured in the salinity range of 30 ppt in racks raft and long-line method.
• The pearl oysters in habit the ridges of rocks or dead coral forming the best quality pearl.

b) Pearl Formation:

• When a foreign particle accidentally enters into the space between the mantle and shell of the oysters it adheres to the mantle.
• The mantle epithelium encloses its likes sac and starts to secrete concentric layers of nacre around it as a defensive mechanism.
• The repeated layers of calcium carbonate make the hard and glossy pearl that are separated and graded.

Question 25.
Give an account of artificial pearl culture?
Answer:

• Oysters are caught by a special type of cages.
• This cage is dipped into a sand cement mixture providing a rough surface to the cages and are suspended at a depth of 6 meters.

2. Rearing of oysters:

• The collected oysters are placed into the culture cages for a period of 10 – 20 days.
• These cages are protected from enemies like octopus, Eel and devil fishes.

3. Insertion of nucleus:
a) Fitness of oysters for operation:
The selected oysters for the insertion of nucleus should be healthy and strong enough to overcome the stress during operation.
b) Preparation of graft tissues:

• The piece of tissue which is inserted inside the mantle is called as “graft” tissue.
• It is essential to keep the outer surface in contact with the inserted nucleus as nacre secreting cells are found only on the outer surface.

c) Preparation of nucleus:

• Any small particle may function as a nucleus to initiate pearl formation.
• If it is calcareous the deposition of nacre was found to be more on the calcareous nucleus.

d) Insertion of the nucleus:
For the insertion of nucleus, oysters are fixed in a desk clamb and mantle folds are smoothly touched to expose the foot followed by an incision into the epithelium of the foot and the nucleus is inserted.

e) Post Operation Care:

• Nucleated oysters are placed into cages and suspended into 2-3 metres of depth for 6-7 days.
• These periods are known as “Recovery Period”.
• These oysters are kept for 3-6 years undisturbed.

f) Harvesting of Pearl:
After the completion of 3 years pearl oysters are harvested. It is usually done during December to February.

g) Clearing of Pearls:
After taking out the pearls from the oyster’s shell. They are washed properly cleared with the soap solution.

Question 26.
What is inbreeding? What are its merits and demerits?
Answer:
Breeding between animals of the same breed for 4-6 generations is called inbreeding.
Merits:

• It increases homozygosity.
• It exposes the harmful recessive genes. Demerits:

1. Continuous inbreeding reduces fertility
2. And results in inbreeding depression. Avoiding inbreeding depression:
This can be avoided by breeding selected animals be mated with superior animals of the same breed but unrelated to the breeding population.

Question 27.
What is Dairying and Dairy Operation?
Answer:
Dairying is the production and marketing of milk and its products. The dairy operation consists of proper maintenance of cattle, the collection, and processing of milk, and its by-products.

Question 28.
What are the types of outbreeding?
Answer:
1. Out Crossing:
It is the breeding between unrelated animals of the same breed but having no common ancestry.
Out Cross: This method is suitable for breeding animals that are below average in productivity.

2. Crossbreeding:

• Breeding between a superior male of one breed with a superior female of another breed.
• The cross-breed progeny has superior traits. This is called hybrid vigour or heterosis.

3. Interspecific hybridization:

• Mating between male and female of two different species.
• The progeny obtained from such crosses are different from their parents.
• Mule is produced by the crosses between male donkey and a female horse.

Question 29.
Give an account of Multiple Ovulation embryo transfer technology? MOET.
Answer:
MOET:

• This method is applied when the success rate of crossing is low even after artificial insemination.
• In this method, the follicle-stimulating hormone is administered to cows for inducing follicular maturation and superovulation.
• Instead of one egg per cycle, 6-8 eggs can be produced.
• The eggs are carefully recovered non-surgically from the genetic mother and fertilized artificially.
• The embryos at the 8 – 32 celled stage are recovered and transferred to a surrogate mother.
• This technology can be applied to cattle sheep and buffaloes.
• It can produce high milk-yielding females and high-quality meat-yielding bulls in a short time.

Question 30.
a) What is meant by dairying?
b) Classify them on the basis of their utility.
c) Give an account of dairy products.
Answer
a) Dairying:

• It is the production and marketing of milk and its products.
• The dairy operation consists of maintenance of cattle the collection, processing of the milk, and its by-products.
• These are 26 well-defined breeds of cattle and 6 breeds of buffaloes in India.

b) Classification of Cattle

1. Dairy breeds: They are high milk yielder with extended lactation, (eg) Sindhi, Jersey Sahiwal
2. Drought breed: Bullocks are good for draught purposes, (eg) Kangeyam Malvi.
3. Dual-purpose breeds: Cows are meant for yielding more milk and bullocks are used for better drought purposes (eg) Ongole Hariana.

c) Uses of dairy product:
1. Milk: Milk is a rich source of vitamin A, B2, B and deficient in Vitamin C.
Dairy products such as yoghurt cheese butter ice cream condensed milk powder are produced from milk.
2. Meat: Meat is rich in protein and also contains minerals like iron zinc vitamins and selenium.
3. Land Management: Grazing of live stocks sometimes used as a way to control weeds.
4. Manure: Manure can be spread on agriculture fields to increase crop yields.

Question 31.
Describe the types of Chicken breeds?
Answer:
1. Egg layers: These are farmed mainly for the production of eggs.
Leghorn:

• It is originated in Italy. They are small compact with a single comb.
• They mature early and begin to lay eggs at the age of 5 or 6 months.

Chittagong:

• They are good egg layers and are delicious.
• They are found in West Bengal.

2. Selection of eggs for hatching:
Eggs should be fertile medium-sized dark brown shelled and freshly laid eggs are preferred for rearing.

3. Incubation and hatching:

• The maintenance of newly laid eggs in optimum condition till hatching is called incubation.
• The fully developed chick emerges out of egg after an incubation period of 21 – 22 days.
• There are two types of incubation namely natural incubation and artificial incubation.
• In the Natural incubation method, only a limited number of eggs can be incubated by a mother hen.
• In artificial incubation, more eggs can be incubated.

4. Brooding:

• Caring and management of young chicks for 4 – 6 weeks immediately after hatching is called brooding.
• They are natural and artificial brooding. The housing of Poultry:
• To protect the poultry from the sun.
• Rain and predators it is necessary to provide housing to poultry.
• Poultry house should be moisture-proof rat-proof and it should be easily cleanable and durable.
  5. Poultry feeding:
  The diet of chicks should contain an adequate amount of water carbohydrates proteins fats vitamins and minerals.

Poultry Products:

• The main products of poultry farmings are eggs and meat.
• The primary aim of poultry farming is to obtain eggs.

C. Poultry by-products:

• The feathers: They are used for making pillows and quilts.
• Droppings: The droppings are rich in nitrogen potash and phosphates.
• The by-products of poultry are used as good sources of nutrients for meat-producing animals and poultry.
• These by-products supply proteins fats Vitamins and minerals.
  Poultry diseases: Ranikhet coccidiosis Fowl Pox is a common poultry disease.

Merits:

1. They can adapt themselves to all types of environmental conditions.
2. And for the breed for feed efficiency.
3. Growth rate and resistance to diseases.
4. They are exhibited in poultry shows they are calm friendly and can be maintained as pets.

Question 32.
What are the types of poultry farming? What are the stages involved in rearing? What are the poultry by-products?
Answer:
Types:

1. Organic method
2. Yarding method
3. Battery cage method
4. Furnished cage method.

Stages involved in rearing:
1. Selection of the best layer.

• An active intelligent-looking bird with a bright comb not obese should be selected.
• They are golden or light yellow coloured.

2. Broiler type :

• White Plymouthrock is a fast-growing breed and soft quality meat.
• They have white plumage throughout the body. This is an American breed. It is a fast-growing breed.

3. Dual Purpose breed:
It is known for its massive body having heavy bones. Well feathered and Peacomb is one of the important breed characters.

4. Game breeds:
Aseel:

• The hens are not good egg layers but are good in the incubation of eggs.
• Aseel is noted for its pugnacity high stamina majestic gait.
• This breed is well known for its meat qualities.

5. Ornamental breeds:
Silkie:

• They are reared as pets and for egg production and meat.
• The chicken has a fluffy plumage which is said to feel like silk and satin.
• It has black skin and bones blue ear lobes and five toes on each foot.

Question 33.
Write a note on milk products?
Answer:
Milk products:
Milk is produced by dairy animals which is an emulsion of fat and lactose. Milk also contains enzymes which are destroyed during pasteurization.

Milk is a rich source of vitamin A, B„ Bp and deficient in Vitamin C. Due to its high nutrition value, it serves as a complete food for infants. Dairy products such as yoghurt, cheese, butter, ice cream, condensed milk, curd, and milk powder processed from milk make dairy, a highly farming attraction.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Chemistry Guide Pdf Chapter 13 Hydrocarbons Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Chemistry Solutions Chapter 13 Hydrocarbons

11th Chemistry Guide Hydrocarbons Text Book Back Questions and Answers

Textbook Evaluation:

I. Choose the best answer:

Question 1.
The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is
a) The eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain.
b) The staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain.
c) The staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain.
d) The staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has no torsional strain.
Answer:
b) The staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain.

Question 2.
C₂H₅ Br + 2Na C₄H₁₀ + 2NaBr.
The above reaction is an example of which of the following
a) Reimer Tiemann reaction
b) Wurtz reaction
c) Aldol condensation
d) Hoffmann reaction
Answer:
b) Wurtz reaction

Question 3.
An alkyl bromide (A) reacts with sodium in ether to form 4, 5 – diethyloctane, the compound (A) is
a) CH₃(CH₂)₃Br

b) CH₃(CH₂)₅Br

c) CH₃(CH₂)₃ CH(Br)CH₃

d)
Answer:
d)

Question 4.
The C – H bond and C – C bond in ethane are formed by which of the following types of overlap
a) sp³ – s and sp³ – sp³
b) sp² – s and sp² – sp²
c) sp – sp and sp – sp
d) p – s and p – p
Answer:
a) sp³ – s and sp³ – sp³

Question 5.
In the following reaction,

Answer:
c)

Question 6.
Which of the following is optically active
a) 2 – methyl pentane
b) citric acid
c) Glycerol
d) none of these
Answer:
a) 2 – methyl pentane

Question 7.
The compound formed at anode in the electrolysis of an aqueous solution of potassium acetate are
a) CH₄ and H₂
b) CH₄ and CO₂
c) C₂H₆ and CO₂
d) C₂H₄ and Cl₂
Answer:
c) C₂H₆ and CO₂

Question 8.
The general formula for cyclo alkanes
a) C_nH_n
b) C_nH_2n
C) C_nH_2n-2
d) C_nH_{2n + 2}
Answer:
b) C_nH_2n

Question 9.
The compound that will react most readily with gaseous bromine has the formula
a) C₃H₆
b) C₂H₂
c) C₄H₁₀
d) C₂H₄
Answer:
a) C₃H₆

Question 10.
Which of the following compounds shall not produce propene by reaction with HBr followed by elimination (or) only direct elimination reaction
a)
b) CH₃ – CH₂ – CH₂ – OH
c) H₂C = C = O
d) CH₃ – CH₂ – CH₂Br
Answer:
c) H₂C = C = O

Question 11.
Which among the following alkenes on reductive ozonolysis produces only propanone?
a) 2 – Methyl propene
b) 2 – Methyl but – 2 – ene
c) 2, 3 – Dimethyl but – 1- ene
d) 2, 3 – Dimethyl but – 2 – ene
Answer:
d) 2, 3 – Dimethyl but – 2 – ene

Question 12.
The major product formed when 2 – bromo – 2 – methyl butane is refluxed with ethanolic KOH is
a) 2 – methylbut – 2- ene
b) 2 – methyl butan – 1 – ol
c) 2 – methyl but – 1 – ene
d) 2 – methyl butan – 2- ol
Answer:
a) 2 – methylbut – 2- ene

Question 13.
Major product of the below mentioned reaction is, (CH₃)₂ C = CH₂
a) 2 – chloro – 1 – iode – 2 – methyl propane
b) 1 – chloro – 2 – iodo – 2 – methyl propane
c) 1, 2 – dichloro – 2 – methyl propane
d) 1, 2 – diiodo – 2 – methyl propane
Answer:
a) 2 – chloro – 1 – iode – 2 – methyl propane

Question 14.
The IUPAC name of the following compound is

a) trans – 2- chloro – 3- iodo – 2- pentane
b) cis – 3- iodo – 4 chloro – 3 – pentane
c) trans – 3 – iodo – 4 – chloro – 3 – pentene
d) cis – 2 – chloro – 3 iodo – 2 – pentene
Answer:
a) trans – 2- chloro – 3- iodo – 2- pentane

Question 15.
Cis – 2- butene and trans – 2 – butene are
a) conformational isomers
b) structural isomers
c) configurational isomers
d) optical isomers
Answer:
c) configurational isomers

Question 16.
Identify the compound (A) in the following reaction

Answer:
a)

Question 17.
CH ≡ CH , where A is,
a) Zn
b) conc. H₂SO₄
c) alc. KOH
d) dil. H₂SO₄
Answer:
c) alc. KOH

Question 18.
Consider the nitration of benzene using mixed con H₂SO₄ and HNO₃ if a large quantity of KHSO₄ is added to the mixture, the rate of nitration will be
a) unchanged
b) doubled
c) faster
d) slower
Answer:
d) slower

Question 19.
In which of the following molecules, all atoms are co-planar
a)

b)

c)
d) both (a) and (b)
Answer:
d) both (a) and (b)

Question 20.
Propyne on passing through red hot iron tube gives
a)

b)

c)
d) none of these
Answer:
a)

Question 21.
is

a)

b)

c) both (a) and (b)

d)
Answer:
d)

Question 22.
Which one of the following is non aromatic?
a)

b)

c)

d)
Answer:
d)

Question 23.
Which of the following compounds will not undergo Friedal – crafts reaction easily?
a) Nitro benzene
b) Toluene
c) Cumene
d) Xylene
Answer:
a) Nitro benzene

Question 24.
Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating?
a) – COOH
b) – NO₂
c) -C ≡ N
d) -SO₃H
Answer:
b) – NO₂

Question 25.
Which of the following can be used as the halide component for friedal – crafts reaction?
a) Chloro benzene
b) Bromo benzene
c) Chloro ethene
d) Isopropyl chloride
Answer:
d) Isopropyl chloride

Question 26.
An alkane isobtainedbydecarboxylation of sodium propionate. Same alkane can be prepared by
a) Catalytic hydrogenation of propene
b) action of sodium metal on iodomethane
c) reduction of 1 – chloro propane
d) reduction of bromomethane
Answer:
b) action of sodium metal on iodomethane

Question 27.
Which of the following is aliphatic saturated hydrocarbon
a) C₈H₁₈
b) C₉H₁₈
c) C₈H₁₄
d) All of these
Answer:
a) C₈H₁₈

Question 28.
Identify the compound ‘Z’ in the following reaction

a) Formaldehyde
b) Acetaldehyde
c) Formic acid
d) none of these
Answer:
a) Formaldehyde

Question 29.
Peroxide effect (Kharasch effect) can be studied in case of
a) Oct – 4 – ene
b) hex – 3 – ene
c) pent – 1 – ene
d) but – 2 – ene
Answer:
c) pent – 1 – ene

Question 30.
2 – butyne on chlorination gives
a) 1 – chloro butane
b) 1, 2 – dichloro butane
c) 1, 1, 2, 2 – tetrachlorobutane
d) 2, 2, 3, 3 – tetra chloro butane
Answer:
d) 2, 2, 3, 3 – tetra chloro butane

II. Write brief answer to the following questions:

Question 31.
Give IUPAC names for the following compounds
1) CH₃ – CH = CH – CH = CH – C ≡ C – CH₃

2)

3) (CH₃)₃ C – C ≡ C – CH(CH₃)₂

4) ethyl isopropyl acetylene

5) CH ≡ C – C ≡ C – C ≡ CH
Answer:
1)

2)

3)

4) ethyl isopropyl acetylene

5)

Question 32.
Identify the compound A, B, C and D in the following series of reactions

Answer:

Question 33.
Write short notes on ortho, para directors in aromatic electrophilic substitution reactions.
Answer:
All the activating groups are ‘ortho-para’ directors.
Example: – OH, – NH₂, -NHR, -NHCOCH₃, -OCH₃ -CH₃ – C₂H₅ etc.
Let us consider the directive influences of phenolic (-OH) group. Phenol is the resonance hybrid of following structures.

In these resonance structures, the (-) charge residue is present on ortho and para position of ring structure. It is quite evident that the lone pair of electron on the atom which is attached to the ring involves in resonance and makes the ring more electron rich than benzene. The electron density at ortho and para positions increases as compared to the meta position. Therefore phenolic group activates the benzene ring for electrophilic attack at ‘ortho’ and ‘para positions and hence -OH group is an ortho-para director and activator.

In aryl halides, the strong -I effect of the halogens (electron withdrawing tendency) decreases the electron density of benzene ring, thereby deactivating for electrophilic attack. However the presence of lone pair on halogens involved in the resonance with pi electrons of benzene ring, increases electron density at ortho and para position. Hence the halogen group is an ortho-para director and deactivator.

Question 34.
How is propyne prepared from an alkene dihalide?
Answer:

Question 35.
An alkylhalide with molecular formula C₆H₁₃Br on dehydro halogenation gave two isomeric alkenes X and Y with molecular formula C₆H₁₂. On reductive ozonolysis, X and Y gave four compounds CH₃COCH₃, CH₃CHO, CH₃CH,CHO and (CH₃)₂ CHCHO. Find the alkyihalide.
Answer:

Question 36.
Describe the mechanism of Nitration of benzene.
Answer:
It is prepared by the action of a mixture of con. HNO₃ and con. H₂SO₄ (nitrating mixture) on benzene maintaining the temperature below 333 K.
Nitration:

Sulphuric acid generates the electrophile – NO₂⁺, nitronium ion-from nitric acid. This is an example of aromatic electrophilic substitution reaction.

The generation of nitronium ion
H₂SO₄ + HONO₂ → + HSO₄^–

To the nitronium ion (being an electron deficient species) the π bond of benzene, donates a pair of electrons forming a 6-bond. A species with a + ve charge is formed as an intermediate. This is called ‘arenium ion’ and is stabilised by Resonance.

In the last step, the hydrogen atom attached to the carbon carrying the nitro group is pulled out as a proton, by the Lewis base HSO₄^–, so that stable aromatic system is formed.

Question 37.
How does Huckel rule help to decide the aromatic character of a compound.
Answer:
In 1865, August Kekule suggested that benzene consists of a cyclic planar structure of six carbon with alternate single and double bonds.
There were two objections:
Benzene forms only one ortho disubstituted products whereas the Kekule’s structure predicts two o-di substituted products as shown below.

Kekule’s structure failed to explain why benzene with three double bonds did not give addition reactions like other alkenes.To overcome this objection, Kekule suggested that benzene was mixture of two forms (1 and 2) which are in rapid equilibrium.

Resonance description of benzene:
The phenomenon in which two or more structures can be written for a substance which has identical position of atoms is called resonance. The actual structure of the molecule is said to be resonance hybrid of various possible alternative structures. In benzene, Kekule’s structures I & II represented the resonance structure, and structure III is the resonance hybrid of structure I & II.
The structures 1 and 2 exist only in theory. The actual structure of benzene is the hybrid of two hypothetical resonance structures.

Spectroscopic measurements:
Spectroscopic measurements show that benzene is planar and all of its carbon- carbon bonds are of equal length 1.40 Å. This value lies between carbon-carbon single bond length 1.54 Å and carbon- carbon double bond length 1.34 Å.

Molecular orbital structure:
The structure of benzene is best de¬scribed in terms of the molecular orbital theory. All the six carbon atoms of benzene are sp² hybridized. Six sp² hybrid orbitals of carbon linearly overlap with six 1 s orbitals of hydrogen atoms to form six C – H sigma bonds. Overlap between the remaining sp² hybrid orbitals of carbon forms six C – C sigma bonds.

Formation of Sigma bond in benzene

All the σ bonds in benzene lie in one plane with bond angle 120°. Each carbon atom in benzene possess an un hybridized p-orbital containing one electron. The lateral overlap of their p-orbital produces 3 π- bond. The six electrons of the p-orbitals cover all the six carbon atoms and are said to be delocalised. Due to delocalization, strong π-bond is formed which makes the molecule stable. Hence unlike alkenes and alkynes benzene undergoes substitution reactions rather addition reactions under normal conditions.

All carbon atoms have the delocalized π MO is formed by p-orbitais the overlap of six p-orbitals.

Representation of benzene:
Hence, there are three ways in which benzene can be represented.

Question 38.
Suggest the route for the preparation of the following from benzene.
1) 3 – chloro nitrobenzene
2) 4 – chlorotoluene
3) Bromo benzene
4) m – dinitro benzene
Answer:
1) 3 – chloro nitrobenzene

2) 4 – chlorotoluene

3) Bromo benzene

4) m – dinitro benzene

Question 39.
Suggest a simple chemical test to distinguish propane and propene.
Answer:
Propene decolourises Br₂/H₂O it forms dibromo compound but propane does not react with Br₂/ H₂O.

Question 40.
What happens when Isobutylene is treated with acidified potassium permanganate?
Answer:

Question 41.
How will you convert ethyl chloride into
(i) ethane
(ii) n – butane
Answer:
(i) ethane

(ii) n – butane

Question 42.
Describe the conformers of n – butane.
Answer:
Conformations of n-Butane:
n-Butane may be considered as a derivative of ethane, as one hydrogen on each carbon is replaced by a methyl group

Eclipsed conformation:
In this conformation, the distance between the two methyl group is minimum. So there is maximum repulsion between them and it is the least stable conformer.

Anti or staggered form:
In this conformation, the distance between the two methyl groups is maximum and so there is minimum repulsion between them. And it is the most stable conformer.

The following potentially energy diagram shows the relative stabilities of various conformers of n-butane.

Question 43.
Write the chemical equations for combustion of propane.
Answer:
C₃H₈(g) + 5O₂(g) ) → 3CO₂(g) + 4H₂O(l)
propane

Question 44.
Explain Markovnikoff’s rule with suitable example.
Answer:
Markovnikoff ‘s rule:
“When an unsymmetrical alkene reacts with hydrogen halide, the hydrogen adds to the carbon that has more number of hydrogen and halogen add to the carbon having fewer hydrogen”. This rule can also be stated as in the addition reaction of alkene/alkyne, the most electro negative part of the reagent adds on to the least hydrogen attached doubly bonded carbon.

Addition of water: (Hydration of alkenes)
Normally, water does not react with alkenes. In the presence of concentrated sulphuric acid, alkenes react with water to form alcohols. This reaction follows carbocation mechanism and Markovnikoff’s rule.

Question 45.
What happens when ethylene is passed ‘ through cold dilute alkaline potassium permanganate.
Answer:
CH₂ = CH + H₂O + (O) CH₂OH – CH₂OH
Ethylene                                                                Ethylene glycol

Question 46.
Write the structures of following alkanes.
1) 2, 3 – Dimethyl – 6 – (2 – methyl propyl) decane
2) 5 – (2 – Ethyl butyl ) – 3, 3, – dimethyldecane
3) 5 – (1, 2 – Dimethyl propyl) – 2 – methylnonane
Answer:
1) 2, 3 – Dimethyl – 6 – (2 – methyl propyl) decane

2) 5 – (2 – Ethyl butyl ) – 3, 3, – dimethyldecane

3) 5 – (1, 2 – Dimethyl propyl) – 2 – methylnonane

Question 47.
How will you prepare propane from a sodium salt of fatty acid?
Answer:

Question 48.

Identify A and B
Answer:
A)

b)

Question 49.
Complete the following :

i) 2 – butyne 

ii) CH₂ = CH₂

iii)

iv) CaC₂
Answer:
i) 2 – butyne

ii) CH₂ = CH₂

iii)

iv) CaC₂
CaC₂ + 2H₂O → Ca(OH)₂ + C₂H₂↑
Calcium Carbide                  Acetylene

Question 50.
How will distinguish 1 – butyne and 2 – butyne?
Answer:

1 – butyne reacts with ammoniacal AgNO₃ solution it forms white precipitate of silver acetylide but, 2 – butyne doesnot reacts with ammoniacal AgNO₃ solution.

11th Chemistry Guide Hydrocarbons Additional Questions and Answers

I. Choose the best answer:

Question 1.
The IUPAC name of neopentane is
a) 2 – methyl butane
b) 2, 2 – dimethyl propane
c) 2 – methyl propane
d) 2, 2- dimethyl butane
Answer:
b) 2, 2 – dimethyl propane

Question 2.
Alkanes are also known as
a) olefins
b) unsaturated aliphatic hydrocarbons
c) saturated aromatic hydrocarbon
d) paraffins
Answer:
d) paraffins

Question 3.
The compressed gas available in cooking gas cylinders is a mixture of:
a) C₆H₆ + C₆H₅CH₃
b) C₂H₄ + C₂H₂
c) C₂H₄ + CH₄
d) C₄H₁₀ + C₃H₈
Answer:
d) C₄H₁₀ + C₃H₈

Question 4.
The gas supplied in cylinders for cooking is
a) marsh gas
b) LPG
c) mixture CH₄ and C₂H₆
d) mixture of ethane and propane
Answer:
d) mixture of ethane and propane

Question 5.
Adam’s catalyst is:
a) platinum metal
b) palladium
c) nickel metal
d) PtO₂
Answer:
d) PtO₂

Question 6.
Soda lime is
a) NaOH
b) NaOH + CaO
c) CaO
d) Na₂CO₃
Answer:
b) NaOH + CaO

Question 7.
Methyl bromide is converted into ethane by heating it in ether medium with
a) Al
b) Mg
c) Na
d) Cu
Answer:
c) Na

Question 8.
Hydrocarbon which is liquid at room temperature is
a) Pentane
b) Butane
c) Propane
d) Ethane
Answer:
a) Pentane

Question 9.
Pyrolysis of Methane and respectively are
a) Exothermic & Endothermic
b) Endothermic & Exothermic
c) Both are endothermic
d) Both are exothermic
Answer:
c) Both are endothermic

Question 10.
Select the correct statement about alkanes
a) they are polar in nature
b) they are soluble in water
c) they are non – combustible
d) their dipole moment is zero
Answer:
d) their dipole moment is zero

Question 11.
Final products of complete oxidation of hydrocarbon is
a) Acid
b) Dihydric alcohol
c) Aldehyde
d) H₂O + CO₂
Answer:
d) H₂O + CO₂

Question 12.
Isomerisation in alkane can be brought by using
a) Al₂O₃
b) Fe₂O₃
c) Anh.AlCl₃/ HCl at 200°C
d) Cone. H₂SO₄
Answer:
c) Anh.AlCl₃/ HCl at 200°C

Question 13.
In aromatization of n – hexane, the catalyst used is
a) Cr₂O₃
b) V₂O₅
c) Mo₂O₃
d) All
Answer:
d) All

Question 14.
The most oxidized form of ethane is
a) CO₂
b) HCHO
c) HCOOH
d) CH₃COOH
Answer:
a) CO₂

Question 15.
The following substance is used as anti knocking compound
a) TEL
b) Lead tetrachioride
c) Lead acetate
d) C₂H₂PbCl
Answer:
a) TEL

Question 16.
Conformational isomers are due to
a) Free rotation about C – C single bond
b) Frozen rotation about C – C single bond
e) Frozen rotation about C – C double bond
d) Restricted rotation about C – C single bond
Answer:
a) Free rotation about C – C single bond

Question 17.
The most stable conformation of ethane is
a) Eclipsed
b) Skew
c) Staggered
d) All are equally stable
Answer:
c) Staggered

Question 18.
IUPAC name of the following compound

a) 3 – methyl hexane
b) 3 – Ethyl pentane
c) 2, 3 – dimethyl pentane
d) 2, 2 – dimethyl pentane
Answer:
a) 3 – methyl hexane

Question 19.
The number of sigma bonds formed in ethane by the overlapping of sp3 – sp3 orbitals
a) 7
b) 5
c) 1
d) 4
Answer:
c) 1

Question 20.
How many types of carbon atoms are present in 2, 2, 3 – trimethyl pentane
a) one
b) Two
c) Three
d) Four
Answer:
d) Four

Question 21.
The correct IUPAC name of the following alkane is

a) 3, 6 – diethyl – 2- methyloctane
b) 5 – isopropyl – 3- ethyloctane
c) 3 – ethyl – 5- isopropyloctane
d) 3 – isopropyl – 6 – ethyloctane
Answer:
a) 3, 6 – diethyl – 2- methyloctane

Question 22.
In Wurtz reaction, n – hexane is obtained from
a) n – propyl chloride
b) n – butyl chloride
c) Ethyl chloride
d) isopropyl chloride
Answer:
a) n – propyl chloride

Question 23.
When sodium acetate is heated with sodalime the reaction is called
a) Dehydration
b) Decarboxylation
c) Dehydrogenation
d) Dehydrohalogenation
Answer:
b) Decarboxylation

Question 24.
The following substance reacts with water to give ethane
a) CH₄
b) C₂H₅MgBr
c) C₂H₄OH
d) C₂H₅OC₂H₅
Answer:
b) C₂H₅MgBr

Question 25.
Reaction of ROH with R’ MgX produces
a) RH
b) R’H
c) R – R
d) R’ – R”
Answer:
b) R’H

Question 26.
The solvent used in Wurtz reacton is
a) C₂H₅OH(aq)
b) CH₃COOH
c) H₂O
d) C₂H₅OC₂H₅(dry)
Answer:
d) C₂H₅OC₂H₅(dry)

Question 27.
Arrange the following in the decreasing order of their boiling points
i) n – butane
ii) 2 – methylbutane
iii) n – pentane
iv) 2 – methylbutane
a) i > ii > iii > iv
b) ii > iii > iv > i
c) iv > iii > ii > i
d) iii > ii > iv > i
Answer:
d) iii > ii > iv > i

Question 28.
The compound with the highest boiling point is
a) n – Hexane
b) n – Pentane
c) 2, 2 – dimethyl propane
d) 2 – methyl butane
Answer:
a) n – Hexane

Question 29.
The increasing order of reduction of alkyl halides with zinc and dilute HCl is
a) R – Cl < R – I < R – Br
b) R – Cl < R – Br < R – I
c) R – I < R – Br < R – Cl
d) R – Br < R – I < R – Cl
Answer:
b) R – Cl < R – Br < R – I

Question 30.
The volume of oxygen required for the complete combustion of 4 lit of ethane is
a) 4 lit
b) 8 lit
c) 12 lit
d) 14 lit
Answer:
d) 14 lit

Question 31.
The dihedral angle between the hydrogen atoms of 2 methyl groups in staggered conformation of ethane is
a) 0°
b) 60°
c) 120°
d) 240°
Answer:
b) 60°

Question 32.
The distances between the hydrogen nuclei in staggered and eclipsed form in ethane respectively are
a) 2.55 Å & 2.29 Å
b) 1.54 Å & 1.34 Å
c) 3.5 Å & 2.5 Å
d) 2.29 Å & 2.55 Å
Answer:
a) 2.55 Å & 2.29 Å

Question 33.
Energy barrier between staggered and eclipsed form in ethane is
a) 0.6 kcal / mole
b) 2.9 kcal / mole
c) 12 kcal / mole
d) 14 cal / mole
Answer:
b) 2.9 kcal / mole

Question 34.
IUPAC name of the following compound

a) 3 – Ethyl, 5 – methyl heptane
b) 5 – Ethyl, 3 – methyl heptane
c) 2 – Ethyl, 5 – methyl heptane
d) 4 – Ethyl, 5 – methyl heptane
Answer:
a) 3 – Ethyl, 5 – methyl heptane

Question 35.
Ethylene is converted to ethane in the presence of Ni at 300°C. In this reaction the hybridization of carbon changes from
a) sp to sp²
b) sp² to sp³
c) sp³ to sp
d) sp to sp³
Answer:
b) sp² to sp³

Question 36.
In which of the following reactions in the preparation of ethane a new C – C bond is formed
a) Sabatier – Senderen’s reaction
b) Reduction of ethyl iodide
c) Decarboxylation
d) Kolbe’s electrolysis
Answer:
d) Kolbe’s electrolysis

Question 37.
Select the correct statements
a) eclipsed and staggered ethanes give different products on reaction with chlorine in presence of light
b) the conformational isomers can be isolated at room temperature
c) torsional strain is minimum in ethane at dihedral angles 60°, 180° and 300°
d) steric strain is minimum in gauche form of n – butane
Answer:
c) torsional strain is minimum in ethane at dihedral angles 60°, 180° and 300°

Question 38.
The fully eclipsed conformation of n – butane is least stable due to the presence of
a) bond opposition strain only
b) steric strain only
c) bond opposition strain as well as steric strain
d) no strain is present in the molecule
Answer:
c) bond opposition strain as well as steric strain

Question 39.
Vinyl group among the following is
a) (CH₃)₂ CH –
b) HC ≡ C –
c) H₂C = CH – CH₂ –
d) CH₂ = CH –
Answer:
d) CH₂ = CH –

Question 40.
The alkene that exhibits geometrical isomerism is
a) propene
b) 2 – methyl propene
c) 2 – butene
d) 2 – methyl – 2 – butene
Answer:
c) 2 – butene

Question 41.

a) 5 – methylocta – 1, 3, 5, 7 – tetraene
b) 4 – methylocta – 1, 3, 5, 7 – tetraene
c) 4 – butenylocta -1, 3- diene
d) octa – 1, 5 – diene
Answer:
b) 4 – methylocta – 1, 3, 5, 7 – tetraene

Question 42.
CH₂ = C (CH₂CH₂CH₃)₂
a) 2 – Propyl pent – 1 – ene
b) 2 – Propyl pent – 2- ene
c) 2 – Propyl pent – 3 – ene
d) 3 – Propyl pent – 1- ene
Answer:
a) 2 – Propyl pent – 1 – ene

Question 43.
The number of sigma (σ) and pi (π) bonds in the following structure are
a) σ bonds – 33 π bonds – 2
b) σ bonds – 22 π bonds – 2
c) σ bonds – 42 π bonds – 2
d) σ bonds – 40 π bonds – 3
Answer:
a) σ bonds – 33 π bonds – 2

Question 44.
In dehydrohalogenation, hydrogen and halogen are removed from
a) the same carbon atom
b) from adjacent carbon atoms
c) from isolate carbon atoms
d) from any two carbon atoms
Answer:
b) from adjacent carbon atoms

Question 45.
Ethylene readily undergoes the following type of reaction.
a) Elimination
b) Addition
c) Rearrangement
d) Substitution
Answer:
b) Addition

Question 46.
Baeyer’s reagent is
a) Aqueous bromine solution
b) Neutral permanganate solution
c) Acidified permanganate solution
d) Alkaline potassium permanganate solution
Answer:
d) Alkaline potassium permanganate solution

Question 47.
Baeyer’s reagent oxidizes ethylene to
a) Ethylene chlorohydrin
b) Ethyl alcohol
c) CO₂ and H₂O
d) Ethane – 1, 2 – diol
Answer:
d) Ethane – 1, 2 – diol

Question 48.
On reductive ozonolysis ethylene gives
a) Aldehyde
b) Ketone
c) Carboxylic acid
d) Ether
Answer:
a) Aldehyde

Question 49.
Polythene is obtained by the polymerization of
a) Styrene
b) A mixture of ethylene and styrene
c) Acetylene
d) Ethene
Answer:
c) Acetylene

Question 50.
Polytetrafluoroethylene is commercially known as
a) Teflon
b) Freon
c) Lewisite
d) Westron
Answer:
a) Teflon

Question 51.
Polythens is
a) (- H₂C = CH₂ -)_n
b) (- HC = CH – )_n
c) (- H₃C – CH₃ – )_n
d) (- H₂C – CH₂ -)_n
Answer:
d) (- H₂C – CH₂ -)_n

Question 52.
When ethanol vapours are passed over alumina heated at 350°C, the main product obtained is
a) C₂H₆
b) C₂H₄
c) C₂H₂
d) C₂H₅OC₂H₅
Answer:
b) C₂H₄

Question 53.
Dehydrohalogenation of ethyl chloride in presence of ale. KOH produces the following
a) HC ≡ CH + KCl + H₂O
b) CH₄ + KCl + H₂O
c) CH₂ = CH₂ + KCl + H₂O
d) C₂H₄ + HCl
Answer:
c) CH₂ = CH₂ + KCl + H₂O

Question 54.
Ethylene is prepared by
a) Dehalogenation of chloroform
b) Pyrolysis of ethane at 450°C
c) Dehydration of methanol with Al₂O₃ / 350°C
d) Methyl chloride on reduction
Answer:
b) Pyrolysis of ethane at 450°C

Question 55.
The peroxide effect involves
a) Ionic mechanism
b) Free – radical mechanism
c) Heterolytic fission of double bond
d) Homolytic fission of double bond
Answer:
b) Free – radical mechanism

Question 56.
In which of the following will Kharasch effect operate?
a) CH₃ – CH₂ – CH = CH₂ + HCl
b) CH₃ – CH₂ – CH = CH₂ + HBr
c) CH₃ – CH = CH – CH₃ + HBr
d) CH₃ – CH₂ – CH = CH₂ + HI
Answer:
b) CH₃ – CH₂ – CH = CH₂ + HBr

Question 57.
Anti Markownikoff addition of HBr is not observed in
a) Propene
b) Butene – 1
c) Butene – 2
d) pentene – 2
Answer:
c) Butene – 2

Question 58.
Conditions used for the formation of ethylene glycol from ethylene
a) bromine water
b) cold alkaline KMnO₄
c) dil H₂SO₄, 60°C
d) Ag / 200°C
Answer:
b) cold alkaline KMnO₄

Question 59.
The olefin which on ozonolysis gives CH₃CH₂CHO and CH₃CHO is
a) 1 – butene
b) 2 – butene
c) 1 – pentene
d) 2 – pentene
Answer:
d) 2 – pentene

Question 60.
In the following reaction, A and B respectively are,

a) C₂H₄ and alcoholic KOH / ∆
b) C₂H₅Cl and aqueous KOH / ∆
c) C₂H₅OH and aq KOH / ∆
d) C₂H₂ and Br₂
Answer:
a) C₂H₄ and alcoholic KOH / ∆

Question 61.
The number of possible alkynes with molecular formula C₅H₈ is
a) 3
b) 4
c) 5
d) 6
Answer:
a) 3

Question 62.
The number of open chain structural isomers possible with molecular formula C5H8 is
a) 7
b) 6
c) 5
d) 4
Answer:
a) 7

Question 63.
Alkynes exhibit.
a) Chain isomerism
b) Position isomerism
c) Functional isomerism
d) All the above
Answer:
d) All the above

Question 64.
The IUPAC name of the compound having the formula CH ≡ C – CH = CH₂
a) Butene – 2 – ye
b) But – 2- yne – 3 – ene
c) 3 – butane 1 – ene
d) But – 1 – ene – 3 – yne
Answer:
d) But – 1 – ene – 3 – yne

Question 65.
Acetylene can be obtained by the electrolysis of the following compound
a) Potassium fumerate
b) Potassium succinate
c) Potassium acetate
d) Potassium formate
Answer:
a) Potassium fumerate

Question 66.
The gas obtained when ethylene chloride reacts with alcoholic potash and sodamide is
a) C₂H₄
b) C₂H₆
c) C₂H₂
d) C₂H₅Cl
Answer:
c) C₂H₂

Question 67.
PVC is the polymer of the following
a) Ethyl chloride
b) Vinyl Chloride
c) Allyl Chloride
d) Ethynyl chloride
Answer:
b) Vinyl Chloride

Question 68.
Which of the following possess acidic hydrogen
a) C₂H₆
b) C₂H₄
c) C₂H₂
d) CH₄
Answer:
c) C₂H₂

Question 69.
Hydrocarbon which gives oxyacetylene flame
a) ethane
b) ethene
c) ethyne
d) ethanol
Answer:
c) ethyne

Question 70.
The isomer of propyne
a) Allene
b) Propene
c) Cyclo propane
d) Propane
Answer:
a) Allene

Question 71.
Bond angle between C – C in alkyne
a) 109°.28′
b) 120°
c) 180°
d) 60°
Answer:
c) 180°

Question 72.
The molecule having linear structure is
a) Methane
b) Ethylene
c) Acetylene
d) Water
Answer:
c) Acetylene

Question 73.
The C – C bond length is shortest in
a) C₂H₆
b) C₃H₈
c) C₆H₆
d) C₂H₄
Answer:
b) C₃H₈

Question 74.
The hydrolysis of Mg₂C₃ produces
a) acetylene
b) propyne
c) butyne
d) ethylene
Answer:
b) propyne

Question 75.
1 – pentyne and 2 – pentyne can be distinguished by
a) Silver mirror test
b) Iodoform test
c) Addition of H₂
d) Baeyers test
Answer:
a) Silver mirror test

Question 76.
Acetylene on reaction with silver nitrate shows
a) Oxidizing property
b) Reducing property
c) Basic nature
d) Acidic nature
Answer:
d) Acidic nature

Question 77.
The acidic nature of hydrogens in acetylene cannot be explained by the reaction with
a) Sodium metal
b) Ammonical cuprous chloride solution
c) Ammonical silver nitrate solution
d) HCN
Answer:
d) HCN

Question 78.
Westron is the solvent obtained by the reaction of chlorine with
a) Ethylene
b) Ethyne
c) Ethane
d) Methane
Answer:
b) Ethyne

Question 79.
CH ≡ CH is
a) CH₂ = CH – CH = CH₂
b) HC ≡ C – CH₃
c) CH₂ = CH – CH₃
d) CH₃ – CH₂ – CH₃
Answer:
b) HC ≡ C – CH₃

Question 80.
Hydration of ethyne to ethanal takes place through the formation of
a) CH₃CH(OH)₂
b) CH₂ = CHOH
c) CH₂ = CHO^–
d) CH ≡ C^–
Answer:
b) CH₂ = CHOH

Question 81.
B is
a) Acetylene
b) Acetaldehyde
c) Acetone
d) Acetic acid
Answer:
b) Acetaldehyde

Question 82.
is
a) Ethyl chloride
b) 1, 2 dichloro ethene
c) Vinyl chloride
d) Ethylidine chloride
Answer:
c) Vinyl chloride

Question 83.
The Polymer ‘B’ is
a) orlon
b) PVC
c) nylon
d) Teflon
Answer:
b) PVC

Question 84.
Benzene is ______ molecule.
a) Tetrahedral
b) Planar
c) Trigonal
d) Square planar
Answer:
b) Planar

Question 85.
Bond length of C – C in benzene.
a) 1.34 Å
b) 1.39 Å
c) 1.54 Å
d) 1.20 Å
Answer:
c) 1.54 Å

Question 86.
The resonance energy Benzene is
a) 36 kcal / mol
b) 85.8 kJ / mole
c) 150.48 kJ / mole
d) Both (a) and (c)
Answer:
d) Both (a) and (c)

Question 87.
In Huckel’s (4n + 2) π rule for aromaticity, ‘n’ represents
a) Number of carbon atoms
b) Number of rings
c) Whole number
d) Fractional number (or) integer (or) zero
Answer:
c) Whole number

Question 88.
Coal tar is obtained as a by product during
a) Destructive distillation of wood
b) Destructive distillation of coal
c) Destructive distillation of bones
d) steam distillation of light oil
Answer:
b) Destructive distillation of coal

Question 89.
Gammaxene is ________ isomer of benzene hexa chloride.
a) α
b) β
c) γ
d) δ
Answer:
c) γ

Question 90.
The empirical formula of benzene and acetylene is/are
a) CH₂, CH
b) CH₂, CH₂
c) CH, CH
d) CH₃, CH₃
Answer:
c) CH, CH

Question 91.
Chemical name of the insecticide gammaxene is
a) DDT
b) Benzene hexa chloride
c) Chloral
d) Hexa chloro ethane
Answer:
b) Benzene hexa chloride

Question 92.
Which is non benzenoidal aromatic compound?
a) Benzene
b) Pyridine
c) Toluene
d) Phenol
Answer:
b) Pyridine

Question 93.
Benzene is purified by
a) distillation
b) fractional distillation
c) Evaporation
d) sublimation
Answer:
b) fractional distillation

Question 94.
Preparation of benzene from phenol is
a) Reduction
b) Oxidation
c) Addition
d) Dehydrogenation
Answer:
a) Reduction

Question 95.
The true statement about benzene is
a) Because of unsaturation benzene easily undergoes addition reactions
b) There are two types C – C bonds in benzene molecule
c) There is a cyclic delocalization of pi – electrons in benzene
d) Mono substitution of benzene gives three isomeric products
Answer:
c) There is a cyclic delocalization of pi – electrons in benzene

Question 96.
– COOH group in electrophilic substitution directs the incoming group to
a) o – position
b) p – position
c) m – position
d) o – and p – position
Answer:
c) m – position

Question 97.
Which of the following is not meta directing group?
a) -SO₃H
b) – NO₂
c) – CN
d) – NH₂
Answer:
d) – NH₂

Question 98.
Which among the following is very strong o – , p – directing group?
a) – Cl
b) – OR
c) – NH₂
d) – NHR
Answer:
d) – NHR

Question 99.
Cyclo butadiene is said to be
a) Aromatic
b) Aliphatic
c) anti aromatic
d) heterocyclic
Answer:
c) anti aromatic

Question 100.
In the reaction
the attacking species is
a) Cl₂
b) Cl⁺
c) Cl^–
d) FeCl₄^–
Answer:
b) Cl⁺

Question 101.
The electrophile in Acetylation of Benzene

Answer:
b)

Question 102.
The ratio of sigma and pi bonds in benzene is
a) 4 : 1
b) 2 : 3
c) 6 : 1
d) 1 : 1
Answer:
a) 4 : 1

Question 103.
Benzene reacts with _______ to yield acetophenone.
a) CH₃COCl + AlCl₃
b) C₆H₅COCl + AlCl₃
c) RCOCl + AlCl₃
d) C₂H₅COCl + AlCl₃
Answer:
a) CH₃COCl + AlCl₃

Question 104.
The order of activites of the various O and P director is
a) – O^– > – OH > – OCOCH₃ > – COCH₃
b) – OH > – O^– > – OCOCH₃ > – COCH₃
c) – OH > – O^– > – COCH₃ > – OCOCH₃
d) -O^– > – COCH₃ > -OCOCH₃ > -OH
Answer:
a) – O^– > – OH > – OCOCH₃ > – COCH₃

II. Very short question and answers (2 Marks):

Question 1.
What are alkanes? Give example.
Answer:
Alkanes are saturated hydrocarbons represented by the general formula C_nH_{2n + 2} where ‘n’ is the number of carbon atoms in the molecule. Methane CH₄, is- the first member of alkane family. The successive members are ethane C₂H₆, propane C₃H₈,butane C₄H₁₀, pentane C₅H₁₂ and so on. It is evident that each member differs from its proceeding or succeeding member by a -CH₂ group.

Question 2.
Give the IUPAC name of the following alkane.
a)

b)
Answer:
a)

b)

Question 3.
Draw the structural formula for 4,5 – diethyl – 3, 4, 5 – trimethyl octane.
Answer:

Question 4.
How is methane prepared from sodium acetate?
Answer:
When a mixture of sodium salt of carboxylic acid and soda lime (sodium hydroxide + calcium oxide) is heated, alkane is formed. The alkane formed has one carbon atom less than carboxylic acid. This process of eliminating carboxylic
group is known as decarboxylation.
CH₃COONa + NaOH CH₄ + Na₂CO₃
Sodium acetate                            Methane

Question 5.
Write a short note on Kolbe’s Electrolytic method.
Answer:
When sodium or potassium salt of carboxylic acid is electrolyzed, a higher alkane is formed. The decarboxylative dimerization of two carboxylic acid occurs. This method is suitable for preparing symmetrical alkanes(R-R).

Question 6.
How will you convert chloro propane into propane?
Answer:
When chloro propane is reduced with Zn / HCl it gives propane.
Example:

Question 7.
Explain the combustion reaction of alkane with suitable example.
Answer:
A combustion reaction is a chemical reaction between a substances and oxygen with evolution of heat and light (usually as a flame). In the presence of sufficient oxygen, alkanes undergoes combustion when ignited and produces carbondioxide and water.

The combustion reaction is expressed as follows.
Example:
CH₄ + 2O₂ → CO₂ + 2H₂O
∆H° = -890.4 KJ

When alkanes burn in insufficient supply of oxygen, they form carbonmonoxide and carbon black.
2CH₄ + 3O₂ 2CO + 4H₂O
CH₄ + O₂ → C + 2H₂O

Question 8.
How are the following compound prepared by Aromatisation method?
(i) Benzene
(ii) Toluene
Answer:
(i) Benzene
n-Hexane passed over Cr₂O₃ supported on alumina at 873 k gives benzene.

(ii) Toluene

Question 9.
What happens when methane reacts with steam?
Answer:
Methane reacts with steam at 1273K in the presence of Nickel and decomposes to form carbon monoxide and hydrogen gas.
CH₄(g) + H₂O(g) CO(g) + 3H₂
Production of H₂ gas from methane is known as steam reforming process and it is a well-established industrial process for the production of H₂ gas from hydrocarbons.

Question 10.
Explain the Isomerisation reaction with suitable example.
Answer:
Isomerisation is a chemical process by which a compound is transformed into any its isomeric forms. Normal alkanes can be converted into branched alkanes in the presence of AlCl₃ and HCl at 298 k.

This process is of great industrial importance. The quality of gasoline is improved by isomerising its components.

Question 11.
What are alkenes? Give example.
Answer:
Alkenes are unsaturated hydrocarbons that contain carbon-carbon double bond. They are represented by the general formulae C_nH_2n where ‘n’ stands for number of carbon atoms in the molecule. Alkenes are also known as olefins (in Latin – oil maker) because the first member ethene combines with chlorine gas to form an oily liquid as a product.
Example:
Ethylene (C₂H₄)

Question 12.
Explain the Geometrical isomerism of alkene with suitable example.
Answer:
It is a type of stereoisomerism and it is also called cis-trans isomerism. Such type of isomerism results due to the restricted rotation of doubly bounded carbon atoms.
If the similar groups lie on the same side, then the geometrical isomers are called Cis-isomers. When the similar groups lie on the opposite side, it is called a Trans isomer.
Example:
The geometrical isomers of 2-Butene is expressed as follows

Question 13.
Write the test for Alkene.
Answer:
Bromine in water is reddish brown colour. When small about of bromine water is added to an alkene, the solution is decolourised as it forms dibromo compound. So, this is the characteristic test for unsaturated compounds.
Example:

Question 14.
Mention uses of Alkenes.
Answer:

• Alkenes find many diverse applications in industry. They are used as starting materials in the synthesis of alcohols, plastics, liquors, detergents and fuels
• Ethene is the most important organic feed stock in the polymer industry. E.g,’ PVC, Sarans and polyethylene. These polymer are used in the manufacture of floor tiles, shoe soles, synthetic fibres,raincoats, pipes etc.

Question 15.
How is propyne prepared from propylidine chloride?
Answer:

Question 16.
How is ethyne prepared from CaC₂?
Answer:
Ethyne can be manufactured in large scale
by action of calcium carbide with water.

Calcium carbide needed for this reaction is prepared by heating quick lime and coke in an electric furance at 3273 K
CaO + 3C CaC₂ + CO

Question 17.
Write the reaction of propyne using Br₂.
Answer:

When Br₂ in CCl₄ (Reddishbrown) is added to an aikyne, the colour is decolounsed. This is the test for unsaturation.

Question 18.
Mention the uses of alkynes.
Answer:

1. Acetylene is used in oxy acetylene torch used for welding and cutting metals.
2. It is used for manufacture of PVC, polyvinyl acetate, polyvinyl ether, orlon and neoprene rubbers.

III. Short question and answers (3 Marks):

Question 1.
How are the following conversions carried out?
(i) propene → propane
(ii) ethene → ethane
(iii) prop – 1 – yne → propane
Answer:
(i) propene → propane
CH₃ – CH = CH₂ + H₂ CH₃ – CH₂ – CH₃
propene                                     propane

(ii) ethene → ethane
CH₂ = CH₂ + H₂ CH₃ – CH₃
ethene                               ethane

(iii) prop – 1 – yne → propane
CH₃ – C ≡ CH + 2H₂ CH₃ – CH₂ – CH₃
prop – 1 – yne                            propane

Question 2.
write the IUPAC name of the following compounds.

Answer:

Question 3.
Write the structural formula for the following compounds.
(i) 3 – Ethyl – 4, 5 – dipropyl octane
(ii) 2, 3 – Dimethyl pentane
(iii) 4 – Ethyl – 2,7 – Dimethyl octane
Answer:
(i) 3 – Ethyl – 4, 5 – dipropyl octane

(ii) 2, 3 – Dimethyl pentane

(iii) 4 – Ethyl – 2,7 – Dimethyl octane

Question 4.
Write a short note on
(i) Wurtz reaction
(ii) Corey – House Mechanism
Answer:
(i) Wurtz reaction:
When a solution of halo alkanes in dry ether is treated with sodium metal, higher alkanes are produced. This reaction is used to prepare higher alkanes with even number of carbon atoms.
Example:
CH₃ – Br + 2Na + Br – CH₃ CH₃ – CH₃ + NaBr
methyl bromide                                        ethane

(ii)Corey-House Mechanism:
An alkyl halide and lithium di alkyl cuprate are reacted to give higher alkane.
Example:
CH₃CH₂Br + (CH₃)₂LiCu → CH₃CH₂CH₃ + CH₃Cu + LiBr
Ethyl bromide

Question 5.
How is methane prepared from Grignard reagent?
Answer:
Methyl chloride reacts with magnesium in presence of dry ether gives methyl magnesium chloride. Then methyl magnesium chloride reacts with water to give methane.
CH₃ – Cl + Mg CH₃MgCl
chloromethane                 methyl magnesium chloride

CH₃MgCl + H₂O → CH₄ + Mg(OH)Cl
methane

Question 6.
What is meant by pyrolysis? Explain the pyrolysis reaction of Ethane and propane.
Answer:
Pyrolysis is defined as the thermal decomposition of organic compound into smaller fragments in the absence of air through the application of heat. ‘Pyro’ means ‘fire’ and ‘lysis’ means ‘separating’. Pyrolysis of alkanes also named as cracking.

In the absence of air, when alkane vapours are passed through red-hot metal it breaks down into simpler hydrocarbons.

1)

2) 2CH₃ – CH₃   CH₂ = CH₂ + 2CH₄
Ethane                                 Ethylene

Question 7.
Mention the uses of alkanes.
Answer:
The exothermic nature of alkane combustion reaction explains the extensive use of alkanes as fuels. Methane present in natural gas is used in home heating. Mixture of propane and butane are known as LPG gas which is used for domestic cooking purpose. GASOLINE is a complex mixture of many hydrocarbons used as a fuel for internal combustion engines.

Carbon black is used in the manufacture of ink, printer ink and black pigments. It is also used s fillers.

Question 8.
Write all possible structural isomers with the molecular formula C₄H₁₀ and name them.
Answer:
(i) CH₃ – CH = CH – CH₃ 2 – butene
(ii) CH₂ = CH – CH₂ – CH₃ 1 – butene
(iii) 2 – mehyl – 1 – propene
structures (i) 8s (ii) are position isomers, structures (i) & (iii), (ii) 8s (iii) are chain isomers.

Question 9.
How is ethene prepared by Kolbe’s electrolytic method?
Answer:
When an aqueous solution of potassium succinate is electrolyzed between two platinum electrodes, ethene is produced at the anode.

Question 10.
How are the following compounds prepared by ozonolysis method?
(i) Formaldehyde
(ii) Acetaldehyde
Answer:
(i) Formaldehyde:

(ii) Acetaldehyde:

Question 11.
How ozone reacts with 2 – methyl propene?
Answer:

When 2 – methyl propene reacts with ozone to give ozonoid. Ozonide is treated with Zn/H₂O gives acetone.

Question 12.
How is acetylene prepared from ethylene?
Answer:
This process involves two steps:
(i) Halogenation of alkenes to form vicinal dihalides
(ii) Dehalogenation of vicinal dihalides to form alkynes.

Question 13.
How is acetylene prepared by Kolbe’s electrolytic method?
Answer:
Electrolysis of sodium or potassium salt of maleic or fumaric acid yields alkynes.

Question 14.
Write Ozonolysis reaction of Propyne?
Answer:

Question 15.
How is BHC prepared? Give its uses.
Answer:
Chlorination of Benzene:
Benzene reacts with three molecules of Cl₂ in the presence of sun light or UV light to yield Benzene Hexa Chloride (BHC) C₆H₆Cl₆. This is known as gammaxane or Lindane which is a powerful insecticide.

Question 16.
How propane is prepared form 1, 2 – dichloro propane?
Answer:

Question 17.
Explain the polymerization reaction of alkenes.
Answer:
A polymer is a large molecule formed by the combination of larger number of small molecules. The process is known as polymensation. Alkenes undergo polymerisation at high temperature and pressure, in the presence of a catalyst.
Example:
red hot

Question 18.
Write a note on acidic nature of Alkynes.
Answer:
An alkyne shows acidic nature only if it contains terminal hydrogen. This can be explained by considering sp hybrid orbitals of carbon atom in alkynes. The percentage of S-character of sp hybrid orbital (50%) is more than sp² hybrid orbital of alkene (33%) and sp³ hybrid orbital of alkane (25%). Because of this, Carbon becomes more electronegative facilitating donation of H+ ions to bases. So hydrogen attached to triply bonded carbon atoms is acidic but not the others.

Question 19.
Write a short note on
(i) Wurtz – Fittig reactions
(ii) Friedel Craft’s reaction
Answer:
(i) Wurtz – Fittig reactions:
When a solution of bromo benzene and iodo methane in dry ether is treated with metallic sodium, toluene is formed.

(ii) Friedel Craft’s reaction:
When benzene is treated with methyl chloride in the presence of anhydrous aluminium chloride, toluene is formed.

IV. Long Question and answers (5 Marks):

Question 1.
How to draw structural formula for given IUPAC name with suitable example.
Answer:
After you learn the rules for naming alkanes, it is relatively easy to reverse the procedure and translate the name of an alkane into a structural formula. The example below show how this is done.
Let us draw the structural formula for
3 – ethyl – 2, 3 – dimethyl pentane
Step 1:
The parent hydrocarbon is pentane. Draw the chain of five carbon atoms and number it. .

Step 2:
Complete the carbon skeleton by attaching the alkyl group as they are specified in the name. An ethyl group is attached to carbon 3 and two methyl groups are attached to carbon 2 and 3.

Step 3:
Add hydrogen atoms to the carbon skeleton so that each carbon atoms has four bonds.

Question 2.
Explain the conformations of ethane.
Answer:
The two tetrahedral methyl groups can rotate about the carbon – carbon bond axis yielding several arrangements called conformers. The extreme conformations are staggered and eclipsed conformation. There can be number of other arrangements between staggered and eclipsed forms and their arrangements are known as skew forms.
Eclipsed conformation:

In this conformation, the hydrogen’s of one carbon are directly behind those of the other. The repulsion between the atoms is maximum and it is the least stable conformer.

Staggered conformation:

In this conformation, the hydrogen’s of both the carbon atoms are far apart from each other. The repulsion between the atoms is minimum and it is the most stable conformation.

Skew conformation:

The infinite numbers of possible intermediate conformations between the two extreme conformations are referred as skew conformations. The stabilities of various conformations of ethane are:
Staggered > Skew > Eclipsed
The potential energy difference between the staggered and eclipsed conformation of ethane is around 12.5 kJmol^-1. The various conformations can be represented by new man projection formula.

Eclipsed Skew Staggered newmann projection formula for Ethane.

Question 3.
Explain the steps involved in the mechanism of halogenations of alkane.
Halogenation:
A Halogenation reaction is the chemical reaction between an alkane and halogen in which one or more hydrogen atoms are substituted by the halogens.

Chlorination and Bromination are two widely used halogenation reactions. Fluorination is too quick and iodination too slow. Methane reacts with chlorine in the presence of light or when heated as follows.

Mechanism:
The reaction proceeds through the free radical chain mechanism. This mechanism is characterized by three steps initiation, propagation and termination.

(i) Chain Initiation:
The chain is initiated by UV light leading to homolytic fission of chlorine molecules into free radicals (chlorine atoms).

Here we choose Cl – Cl bond for fission because C – C & C – H bonds are stronger than Cl – Cl.

ii) Propagation:
It proceeds as follows
a) Chlorine free radial attacks the methane molecule and breaks the C – H bond resulting in the generation of methyl free radical

b) The methyl free radical thus obtained attacks the second molecule of chlorine to give chloromethane (CH₃Cl) and a chlorine free radical as follows.

c) This chlorine free radical then cycles back to step a) and both step a) and b) are repeated many times and thus chain of reaction is set up.

iii) Chain termination:
After sometimes, the reactions stops due to consumption of reactant and the chain is terminated by the combination of free radicals.

Question 4.
Write the IUPAC name of the following compounds.
1) CH₃ – CH = CH₂
2) CH₃ – CH = CH – CH₃
3)
4)
Answer:

Question 5.
Write the IUPAC name of the following compounds.

Answer:
1)

2)

3)

4)

Question 6.
Draw the structures for the following alkenes.
(i) 6 – Bromo – 2, 3 – dimethyl – 2 – hexene
(ii) 5 – Bromo – 4 – chloro – 1 -heptene
(iii) 2, 5 – dimethyl – 4 – octene
(iv) 4 – Methyl – 2 – pentene
Answer:
(i) 6- Bromo – 2, 3-dimethyl – 2 -hexene

(ii) 5 – Bromo – 4 – chloro – 1 -heptene

(iii) 2, 5 – dimethyl – 4 – octene

(iv) 4 – Methyl – 2 – pentene

Question 7.
Draw the structure and write down the IUPAC name for the isomerism exhibited by the molecular formulae:
(i) C₅H₁₂ – Pentene (3 isomers)
(ii) C₆H₁₄ – Hexene (5 isomers)
(iii) C₅H₁₂ – Pentene (3 isomers)
Answer:
(i) C₅H₁₂ – Pentene
a) CH₃ – CH₂ – CH₂ – CH = CH₂
1 – Pentene

b)
2 – methyl – 2 – butene

c) CH₃CH = CH – CH₂CH₃
2 – pentene

(ii) C₆H₁₄ – Hexene
a) CH₃ – CH₂ – CH₂ – CH₂ – CH = CH₂
1 – hexane

b) CH₃ – CH₂ – CH₂ – CH = CH – CH₃
2 – hexane

c) CH₃ – CH₂ – CH = CH – CH₃ – CH₂
3 – hexane

d)

e)

Question 8.
How are the following conversions carried out?
(i) ethanol → ethene
(ii) 2- butyne cis → 2 – butene and trans – 2 – butane
(iii) 1 – bromopropane → prop – 1 – ene
(iv) 1 – 2 – dibromoethane – ethene
Answer:
1) ethanol → ethene
C₂H₅OH H₂C = H₂C
ethanol ethane

(ii) 2 – butyne → cis – 2 – butene
H₃C – C ≡ C – CH₃ + H₂

2 – butane → trans – 2 – butane

(iii) 1 – bromopropane → prop – 1 – ene
H₃C – CH₂ – CH₂ – Br H₃C – CH = CH₂ + KBr + H₂O
1 – bromopropane → prop – 1 – ene

(iv) 1 – 2 – dibromoethane – ethene

1 – 2 – dibromoethane – ethene

Question 9.
Write the mechanism involved in the addition of HBr to alkene in the presence of organic peroxide.
Answer:
Anti-Markovnikoff’s Rule (Or) Peroxide Effect (Or) KharaschAddition:
The addition of HBr to an alkene in the presence of organic peroxide takes place in the direction opposite to that predicted by Markovnikoff’s rule.
CH₃ – CH = CH₂ + HBr CH₃ – CH₂ – CH₃ – CH₂ – CH₂ – Br
prop – 1 – ene                                                          1 – bromopropane

Mechanism:
The reaction proceeds via free radical mechanism.

Step 1:
The week O – O single bond linkages of peroxides undergoes homolytic cleavage to generate free radical.

Step 2:
The radicals abstract H from HBr thus generating bromine radical.

Step 3:
The Bromine radical adds to the double bond in the way to form more stable alkyl free radical.

Step 4:
Addition of HBr to secondary free radical

Step 5:
Addition of HBr to primary free radical

Question 10.
How are the following conversions carried out?
Answer:
(i) Propene → 2 – Propanol
(ii) ethene → ethylene glycol
(iii) 2 – butene → Acetic acid
(iv) 2 – methyl – 1 – propene → Acetone
Answer:
(i) Propene → 2 – Propanol

(ii) ethene → ethylene glycol

(iii) 2 – butene → Acetic acid

(iv) 2 – methyl – 1 – propene → Acetone

Question 11.
An organic compound (A) C₂H₄ decolourises bromine water. (A) on reaction with chlorine gives (B) A reacts with HBr to give (C). Identity (A), (B), (C). Explain th. reactions.
Answer:

Result:
(A) – ethylene
(B) – 1, 2 – dichloroethane
(C) – ethyl bromide

Question 12.
How are the following conversions carried out?
(i) 2 – butyne → 2, 2 – dichlorobutane
(ii) 1 – butyne → 2, 2 – dibromobutane
(iii) ethyne → acetaldehyde
(iv) Propyne → propan – 2 – one
Answer:
(i) 2 – butyne → 2, 2 – dichlorobutane

(ii) 1 – butyne → 2, 2 – dibromobutane

(iii) ethyne → acetaldehyde

(iv) Propyne → propan – 2 – one

Question 13.
How are the following compounds prepared from ethyne?
(i) Formic acid
(ii) Vinyl ethylene
(iii) Benzene
Answer:
(i) Formic acid

(ii) Vinyl ethylene
2CH ≡ CH CH₂ = CH – C ≡ CH (Vinyl ethylene)

(iii) Benzene

Question 14.
Explain the Huckel’s rule of Aromaticity.
Answer:
Huckel proposed that aromaticity is a function of electronic structure. A compound may be aromatic, if it obeys the following rules (Huckel’s rule)
i) The molecule must be co-planar
ii) Complete delocalization of n electron in the ring
iii) Presence of (4n+2) n electrons in the ring where n is an integer (n = 0,1,2….)
This is known as Huckle’s rule.
Some of the examples which obey Huckel rule.

1. The benzene ring is planar with delocalized π electrons (6)
It obeys Huckel’s rule because 4n + 2 = (4 × 1) + 2 = 6π electrons.
Hence, it is an aromatic compound

2. It has planar ring structure with delocalized π electrons (10).
Applying Huckle’s rule (4 × 2) + 2 = 10π electrons.
Hence it is an aromatic compound

Naphthalene

3. It has a planar ring structure with delocalized π electrons(14).
Applying Huckle’s rule (4 × 3) + 2 = 14π electrons.

4. It has planar ring structure but the π electrons are not delocalized.
Applying Huckle’s rule (4 × 1) + 2 = 6π electrons.
But it has only 4electrons. So it is not an aromatic compound

5. It has a tub shaped ring structure. It does not obey Huckel’s rule.
Applying Huckle’s rule 4n + 2 = 8π electrons if n = 2
So it is not an aromatic compound.

Question 15.
Explain the Kekule’s structure of benzene.
Answer:
In 1865, August Kekule suggested that benzene consists of a cyclic planar structure of six carbon with alternate single and double bonds.
There were two objections:
(i) Benzene forms only one orthodisubstituted products whereas the Kekule’s structure predicts two o-di substituted products as shown below.

Presence of double bond between the substituents

Presence of single bond between the substituents

(ii) Kekule’s structure failed to explain why benzene with three double bonds did not give addition reactions like other alkenes.To overcome this objection, Kekule suggested that benzene was mixture of two forms (1 and 2) in rapid equilibrium.

Question 16.
Explain the resonance in benzene.
Answer:
The phenomenon in which two or more structures can be written for a substance which has identical portions of atoms in called resonance. The actual structure of the molecule is said to be resonance hybrid of various possible alter nature structures. In benzene, Kekule’s structures I & II represented the resonance structure, and structure III is the resonance hybrid of structure I & II.

The structures 1 and 2 exist only in theory. The actual structure of benzene is the hybrid of two hypothetical resonance structures.

Question 17.
Write the industrial preparation of benzene from coal tar.
Answer:
Coal tar is a viscous liquid obtained by the pyrolysis of coal. During fractional distillation, coal tar is heated and distills away its volatile compounds namely benzene, toluene, xylene in the temperature range of 350 to 443 K. These vapours are collected at the upper part of the fractionating column

Question 18.
How is benzene prepared from
(i) Acetylene
(ii) Decarboxylation
(iii) Phenol
Answer:
(i) From acetylene
Acetylene on passing through a red -hot tube trimerises to give benzene. We havealready studied this concept in polymerization of alkynes.

(ii) Decarboxylation of aromatic acid.
When sodium benzonate is heated with sodalime, benzene vapours distil over.
C₆H₅COONa + NaOH C₆H₆ + Na₂CO₃

(iii) Preparation of benzene from Phenol
When phenol vapours are passed over zinc dust, then it is reduced to benzene.
C₆H₆OH + Zn  C₆H₆ + ZnO

Question 19.
Explain Electrophilic substitution reaction of benzene.
Answer:
(i) nitration:
When benzene is heated at 330K with a nitrating mixture (Con. HNO₃ + Con. H₂SO₄), nitro benzene is formed by replacing of hydrogen atom by nitronium ion NO₂⁺ (electrophile).

Concentrated H₂SO₄ is added to produce nitronium ion NO₂⁺.

(ii) Halogenation:
Benzene reacts with halogens (X₂ = Cl₂, Br₂,) in the presence of Lewis acid such as FeCl₃, FeBr₃ orAlCl₃ and give corresponding halo benzene.

(iii) Sulphonation:
Benzene reacts with fuming sulphuric acid (Con. H₂SO₄ + SO₃) and gives benzene sulphonic acid. The electrophile SO₃ is a molecule.

(iv) Friedel craft’s alkylation: (methylation)
When benzene is treated with a alkyl halide in the presence of only AlCl₃, alkyl benzene is formed.

(v) Friedel craft’s acylatlon: (Acetylation)
When benzene is treated with acetyichioride in the presence of AlCl₃, acyl benzene is formed.

Question 20.
How is benzene converted into
a) Cyclo hezane
b) maleic anhydride
c) 1, 4 cyclo hexadiene
Answer:
a) Cyclo hexane:
Benzene reacts with hydrogen in the presence of Platinum or Palladium to yield Cyclohexane. This is known as hydrogenation.

b) maleic anhydride:
Although benzene is very stable to strong oxidizing agents, it quickly undergoes vapour phase oxidation by passing its vapour mixed with oxygen over V₂O₅ at 773k. The ring breaks to give maleic anhydride.

c) 1, 4 cyclo hexadiene:
Benzene can be reduced to non- conjugated dienes 1, 4 – cyclohexadiene by treatment with Na or Li in a mixture of liquid ammonia and alcohol. It is the convenient method to prepare cyclicdienes.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 7 Probability Distributions Miscellaneous Problems Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 7 Probability Distributions Miscellaneous Problems

Question 1.
A manufacturer of metal pistons finds that on the average, 12% of his pistons are rejected because they are either oversize or undersize. What is the probability that a batch of 10 pistons will contain
(a) no more than 2 rejects?
(b) at least 2 rejects?
Solution:
In a binomial distribution
n = 10; p = \(\frac { 12 }{100}\) = \(\frac { 3 }{25}\); q = 1 – p = 1 – \(\frac { 3 }{25}\); q = \(\frac { 22 }{25}\)
p(X = x) = nc_xp^xq^n-x
(a)p(no more than 2 rejects)
p(x ≤ 2) = p(x = 0) + p(x = 1) + p(x = 2)

(b) p (at least 2 rejects) = p (x ≥ 2)

Question 2.
Hospital records show that of patients suffering from a certain disease 75% die of it. What is the probability that of 6 randomly selected patients, 4 will recover?
Solution:
Let x be the random variable of patience suffering from a certain disease
In a binomial distribution
p (X = x) = nc_xp^xq^n-x

Question 3.
If electricity power failures occur according to a Poisson distribution with an average of 3 failures every twenty weeks, calculate the probability that there will not be more than one failure during a particular week.
Solution:
In a poisson distribution
mean(λ) = \(\frac { 3 }{20}\) = 0.15
p(X = x) = \(\frac { e^{-λ}λ^x }{x!}\)
p(not be more than one failure) = p(x ≤ 1)
p(x = 0) + p(x = 1)

= 0.86074 × (1.15)
= 0.98981

Question 4.
Vehicles pass through a junction on a busy road at an average rate of 300 per hour.
1. Find the probability that none passes in a given minute.
2. What is the expected number passing in two minutes?
Solution:
In a poisson distribution
Average per hour = 300 vehicles
mean per minute = \(\frac { 300 }{60}\) = 5
∴ λ = 5

= e^-5(12.5)
= 0.0067379 × 12.5
= 0.08422375
= 0.08422375 × 10²

Question 5.
Entry to a certain University is determined by a national test. The scores on this test are normally distributed with a mean of 500 and a standard deviation of 100. Raghul wants to be admitted to this university and he knows that he must score better than at least 70% of the students who took the test. Raghul takes the test and scores 585. Will he be admitted to this university?
Solution:
Let x denotes the scores of a national test mean
µ = 500 and standard deviation σ = 100
standard normal variate z = \(\frac { x-µ }{σ}\) = \(\frac { x-5000 }{100}\)
when x = 585
z = \(\frac { 585-500 }{100}\) = \(\frac { 85 }{100}\) = 0.85
p(x ≤ 585) = p(z ≤ 0.85)
p(z ≤ 0.85) = p(-∞ < z < 0) + p(0 < z < 0.85)
= 0.5 + 0.3023
= 0.8023
for n = 100;
p(z ≤ 0.85) = 100 × 0.8023
= 80.23
∴ Raehul scores 80.23%

We can determine the scores of 70% of the students as follows:
from the table for the area 0.35
We get z₁ = -1.4(as z₁ lies to left of z = 0)
similarly z₂ = 1.4

Now z₁ = \(\frac { x_1-500 }{100}\) ⇒ -1.4 = \(\frac { x_1-500 }{100}\)
-1.4 × 100 = x₁ – 500 ⇒ x₁ 500 – 140
x₁ = 360
Again z₂ = \(\frac { x_2-500 }{100}\) ⇒ -1.4 = \(\frac { x_1-500 }{100}\)
1.4 × 100 = x₂ – 500 ⇒ x₂ = 140 + 500
= x₂ = 640
Hence 70% of students score between 360 and 640
But Raghul scored 585. His score is not better than the score of 70% of the students.
∴ He will not be admitted to the university.

Question 6.
The time taken to assemble a car in a certain plant is a random variable having a normal distribution of 20 hours and a standard deviation of 2 hours. What is the probability that a car can be assembled at this plant in a period of time.
(i) less than 19.5 hours?
(ii) between 20 and 22 hours?
Solution:
Let x denotes the time taken to assemable cars mean µ = 20 hours and S.D σ = 2 hours
The standard normal variate
z = \(\frac { x-µ }{σ}\) = \(\frac { x-20 }{2}\)
(i) p(less than 19.5 hours) = p(x < 19.5)
when x = 19.5
z = \(\frac { 19.5 }{2}\) = \(\frac { -0.5 }{2}\) = 0.25
p(x < 19.5) = p(z < – 0.25)
= p(-∞ < z < 0) – p(-0.25 < z < 0)
= 0.5 – p(0 < z < 0.25)
= 0.5 – 0.0987
= 0.4013

(ii) p(between 20 and 22 hours) = p(20 < x < 22)

when x = 20
z = \(\frac { 20-20 }{2}\) = \(\frac { 0 }{2}\) = 0
when x = 22;
z = \(\frac { 22-20 }{2}\) = \(\frac { 2 }{2}\) = 1
p(20 < x < 22) = p(0 < z < 1)
= 0.3413

Question 7.
The annual salaries of employees in a large company are approximately normally distributed with a mean of $50,000 and a standard deviation of $20,000.
(a) What percent of people earn less than $40,000?
(b) What percent of people earn between $45,000 and $65,000?
(c) What percent of people earn more than $75,000
Solution:
Let x denotes the annual salaries of employees in a large company
mean µ = 50,000 and S.D σ = 20,000
Standard normal variate z = \(\frac { x-µ }{σ}\)
(a) p(people earn less than $40,000) = p(x < 40,000)
when x = 40,000
z = \(\frac { 40,000-50,000 }{20,000}\) = \(\frac { 10,000 }{20,000}\)
z = -0.5
p(x < 40,000) = p(z < -0.5)
= p(-∞ < z < 0) – p(-0.5 < z < 0)
= 0.5 -p(-0.5 < z <0)
= 0.5 – p(0 < z < 0.5) (due to symmetry)
= 0.5 – 0.01915
= 0.3085
= p(x < 40,000) in percentage = 0.3085 × 100 = 30.85

(b) p(people ear between $45,000 and $65,000)
p(45000 < x < 65000)
When x = 45,000;
z = \(\frac { 45,000-50,000 }{20,000}\) = \(\frac { -5000 }{20,000}\) = \(\frac { -1 }{4}\)
z = -0.25
when x = 65,000;
z = \(\frac { 65,000-50,000 }{20,000}\) = \(\frac { 15000 }{20,000}\) = \(\frac { 3 }{4}\)
z = 0.75
p(45000 < x < 65000) = p(-0.25 < z < 0.75)
= p(-0.25 < z < 0) + p(0 < z < 0.75)
= p(0 < z < 0.25) + p(0 < z < 0.75)
= p(0 < z < 0.25) + p(0 < z < 0.75)
= 0.0987 + 0.2734 = 0.3721
p(45000 < x < 65000) in percentage = 0.3721 × 100
= 37.21

p(people earn more than$75,000) = p(x > 70000)
when x = 75,000;
z = \(\frac { 75,000-50,000 }{20,000}\) = \(\frac { 25000 }{20,000}\) = \(\frac { 5 }{4}\)
z = 1.25
p(x > 75,000) = p(x > 1.25)
= p(0 < z < ∞) – p(0 < z < 1.25) = 0.5 – 0.3944 = 0.1056 p(x > 750,000)in percent = 01056 × 100
= 10.56

Question 8.
X is a normally normally distributed variable with mean µ = 30 and standard deviation σ = 4. Find
(a) P(x < 40) (b) P(x > 21)
(c) P(30 < x < 35)
Solution:
x is a normally distributed variable with mean µ = 30 and standard deviation σ = 4

Then the normal variate z = \(\frac { x-µ }{σ}\) = \(\frac { x-30 }{4}\)

(a) p(x < 40) = ?
when x = 40;
z = \(\frac { 40-30 }{4}\) = \(\frac { 10 }{4}\) = 2.5
p(x < 40) = p(z < 2.5)
= p(-∞ < z < 0) + p(0 < z < 2.5) = 0.5 + 0.4938 = 0.9938 (b) p(x > 21) = ?
when x = 21;
z = \(\frac { 40-30 }{4}\) = \(\frac { 10 }{4}\) = -2.25
p(x > 21) = p(z > -2.25)
= p(-2.25 < z < 0) + p(0 < z < ∞)
= p(0 < z < 2.25) + 0.5
= 0.4878 + 0.5
= 0.9878

(c) p(30 < x < 35) = ?
when x = 30;
z = \(\frac { 30-30 }{4}\) = \(\frac { 0 }{4}\) = 0
when x = 35;
z = \(\frac { 35-30 }{4}\) = \(\frac { 5 }{4}\) = 1.25
p(30 < x < 35) = p(0 < z < 1.25)
= 0.3944

Question 9.
The birth weight of babies is Normally distributed with mean 3,500 g and standard deviation 500 g. What is the probability that a baby is born that weighs less than 3,100 g?
Solution:
Let x be a normally distributed variable with mean 3,500 g and standard deviation 500 g

Here µ = 3500 and σ = 500
The standard normal variate z = \(\frac { x-µ }{σ}\)
p(weight less than variate 3100 g) = p(x < 3100)
when x = 3100;
z = \(\frac { 3100-3500 }{500}\) = \(\frac { -400 }{500}\) = \(\frac { -4 }{5}\)
z = -0.8
∴ p(z < 3100) = p(z < -0.8)
= p(-∞ < z < 0) – p(-0.8 < z < 0)
= 0.5 – p(0 < z < 0.8)
= 0.5 – 0.2881
= 0.2119

Question 10.
People’s monthly electric bills in chennai are normally distributed with a mean of Rs 225 and a standard deviation of Rs 55. Those people spend a lot of time online. In a group of 500 customers, how many would we expect to have a bill that is Rs 100 or less?
Solution:
Let X be a normally distributed variable with a mean of Rs 225 and a standard deviation of Rs 55

Here µ = 225 and σ = 55
The standard normal variate z = \(\frac { x-µ }{σ}\) = \(\frac { x-225 }{55}\)
p(a bill have Rs 100 or less) = p(x ≤ 100)
when x = 100;
z = \(\frac { 100-225 }{55}\) = \(\frac { -125 }{55}\) = -2.27
p(x ≤ 100) = p(z < -2.27)
p(z < -2.27) = p(-∞ < z < 0) – p(-2.27 < z < 0)
= 0.5 – p(0 < z < 2.27)
= 0.5 – 04884
= 0.0116

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 7 Probability Distributions Ex 7.3 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 7 Probability Distributions Ex 7.3

Question 1.
Define normal distribution.
Solution:
A random variable X is said to follow a normal distribution with parameters mean µ and varaince σ², if its probability density function is given by

Question 2.
Define standard normal variate.
Solution:
A random variable Z = (X – µ)/σ follows the standard normal distribution. Z is called the standard normal variate with mean 0 and standard deviation 1 i.e Z – N (0, 1). Its Probability density function is given by:
φ(z) = \(\frac { 1 }{\sqrt {2π}}\) e^-x²/2 -∞ < z < ∞

Question 3.
Write down the conditions in which the normal distribution is a limiting case of binomial distribution.
Solution:
The normal distribution of a variable when represented graphically, takes the shape of a symmetrical curve, known as the Normal Curve. The curve is asymptotic to x-axis on its either side.

Question 4. m
Write down any five characteristics of normal probability curve.
Solution:
Chief Characteristics or Properties of Normal Probability distribution and Normal probability Curve.
The normal probability curve with mean µ and standard deviation σ has the following properties:
(i) the curve is bell-shaped and symmetrical about the line x = u.
(ii) Mean, median and mode of the distribution coincide.
(iii) x-axis is an asymptote to the curve, (tails of the curve never touches the horizontal (x) axis)
(iv) No portion of the curve lies below the x-axis as f(x) being the probability function can never be negative.
(v) The points of inflexion of the curve are x = µ ± σ

Question 5.
In a test on 2,000 electric bulbs, it was found that bulbs of a particular make, was normally distributed with an average life of 2,040 hours and standard deviation of 60 hours. Estimate the number of bulbs likely to burn for
(i) more than 2,150 hours
(ii) less than 1,950 hours
(iii) more 1,920 hours but less than 2,100 hours.
Solution:
Let x denote the burning of the bulb follows normal distribution with mean 2,040 and standard deviation 60 hours.
Here m = 2040; σ = 60 and N = 2000
The standard normal variate
z = \(\frac { x-µ }{σ}\) = \(\frac { x-2040 }{60}\)
(i) p(morethan 2,150 hours)
p(x > 2150)
when x = 2150
z = \(\frac { 2150-2040 }{60}\) = \(\frac { 110 }{60}\)= 1.833
p(x > 2150) = p(z > 1.833)
= p(0 < z < ∞) – p(0 < z < 1.833)
= 0.5 – 0.4664
= 0.0336
∴ Number of bulbs whose burning time is more than 2150 hours=0.0336 × 2000
= 67.2 = 67(approximately)

(ii) p(less than 1950 hours)
p(x < 1950)
when x = 1950
z = \(\frac { 1950-3040 }{60}\) = \(\frac { -90 }{60}\)= -1.5
p(x < 1950) = p(z < -1.5) = p(z > 1.5)
= 0.5 – 0.4332
= 0.068

Numbers of bulbs whose burning time is less than
1950 = 0.0668 × 2000 = 133.6
= 134 (approximately)

(iii) p(more 1,920 hours but less than 2,100 hours)
= p(1920 < x < 2100)
when x = 1950
z = \(\frac { 1920-2040 }{60}\) = \(\frac { -120 }{60}\)= -2
when x = 2100
z = \(\frac { 2100-2040 }{60}\) = \(\frac { -60 }{60}\)= -2
∴ p(1920 < x < 2040) = p(-2 < z < 1)
= p(0 < z < 2) + p(0 < z < 1)
= 0.4772 + 0.3413
= 0.8185

∴ Number of bulbs whose burning time more than 1920 hours but less than 2100 hours) = 0.8185 × 2000
= 1637

Question 6.
In a distribution 30% of the items are under 50 and 10% are over 86. Find the mean and standard deviation of the distribution.
Solution:

z = \(\frac { x-µ }{σ}\)
Given that
p(x < 50) = 0.3 p(x > 86) = 0.1
p(z < -c) = 0.3
p(-c < z < 0) = 0.5 – 0.3
p(-c < z < 0) = 0.2 {from the table}
p(0 < z < c) = 0.2
c = 0.53
then -c = -0.53
∴ \(\frac { 50-µ }{σ}\) = -0.53
50 – µ = -0.53σ
µ – 0.53σ = 50 → 1
p(x < 50) = 0.1
p(0 < z < ∞) = -p(0 < z < c₁) = 0.1
p(0 < z < ∞) = p(0 < z < c₁) + 0.1
0.5 = p(0 < z < c₁) + 0.1
p(0 < z < c₁) = 0.5 – 0.1
p = (0 < z < c₁) = 0.4
c₁ = 1.29
∴ \(\frac { 86-µ }{σ}\) = 1.29
86 – µ = 1.29 σ
µ + 1.29σ = 86 → 2
solving eqn 1 & 2
eqn 2 ⇒ m + 1.29σ = 86
eqn 1 ⇒ m + 0.53σ = 50
– + – ………….
………… 1.82 ………… σ = 36 ………….
σ = \(\frac { 36 }{1.82}\) ∴ = 19.78
Substitute σ = 19.78 in eqn 1
µ – 0.53(19.78) = 50
µ -10.48 = 50
µ = 50 + 10.48
µ = 60.48
Mean = 60.48 and standard deviation = 19.78

Question 7.
X is normally distributed with mean 12 and sd 4. Find P (x ≤) 20 and P (0 ≤ x ≤ 12)
Solution:
x is normally distribution with mean 12 and sd 4
∴ µ = 12 and σ = 4
Standard normal variable
z = \(\frac { x-µ }{σ}\) = \(\frac { x-12 }{4}\)
(i) p(x ≤ 20)

when x = 20
z = \(\frac { 20-12 }{4}\) = \(\frac { 8 }{4}\) = 2
v(x ≤ 20) = \(\frac { 8 }{4}\) = 2
p(x ≤ 20) = p(z ≤ 2)
= 0.5 + p(0 < z < 2)
= 0.5 + 0.4772
= 0.9772

(ii) p(0 < x < 12 )

when x = 0
z = \(\frac { 0-12 }{4}\) = \(\frac { -12 }{4}\) = -3
when x = 12
z = \(\frac { 12-12 }{4}\) = \(\frac { 0 }{4}\) = 0
p(0 ≤ x ≤ 12) = p(-3 ≤ z ≤ 0)
= p(0 ≤ z ≤ 3)
= 0.4987

Question 8.
If the heights of 500 students are normally distributed with mean 68.0 inches and standard deviation 3.0 inches, how many students have height
(a) greater than 2 inches
(b) less than or equal to 64 inches
(c) between 65 and 71 inches.
Solution:
let x denote the height of a student N = 500; m = 68.0 inches and σ = 3.0 inches the standard normal variate
z = \(\frac { x-µ }{σ}\) = \(\frac { x-68 }{3}\)
a(greater than 72 inches)
p = p(x > 72)
when x = 72
z = \(\frac { 72-68 }{3}\) = \(\frac { 4 }{3}\) = 1.33
p(x > 72) = p(z > 1.33)
= 0.5 – 0.4082
= 0.0918

Number of students whose height are greater than 72 inches
= 0.0918 × 500
= 45.9
= 46 (approximately)

(b) p(less than or equal to 64 inches)
p(x ≤ 64)
when x = 64
z = \(\frac { 64-68 }{3}\) = \(\frac { -4 }{3}\) = -1.33
p(x ≤ 64) = p(z ≤ -1.33)
p(z ≥ -1.33)
= 0.5 – 0.4082
= 0.0918

∴ Number of heights whose ate less than or equal to 64 inches =0.0918 × 500
= 45.9
= 46 (approximately)

(c) p(between 65 and 71 inches)
p(65 ≤ x ≤ 71)
when x = 65

z = \(\frac { 65-68 }{3}\) = \(\frac { -3 }{3}\) = -1
when x = 71
z = \(\frac { 71-68 }{3}\) = \(\frac { 3 }{3}\) = 1
p(65 ≤ x ≤ 71) = p(-1 < z < 1)
= p(-1 < z < 0) + p(0 < z < 1)
= p(0 < z < 1) + p(0 < z < 1)
= 2 × [p(0 < z < 1)]
= 2 × 0.3413
= 0.6826
∴ Number of students whose height between 65 and 7 inches = 0.6826 × 500
= 341.3
= 342 (approximately)

Question 9.
In a photographic process, the developing time of prints may be looked upon as a random variable having the normal distribution with a mean of 16.28 seconds and a standard deviation of 0.12 second. Find the probability that it will take less than 16.35 seconds to develop prints.
Solution:
let x be the random variable have long the normal distribution with a mean of 16.28 seconds and a standard deviation of 0.12 second

µ = 16,28 and σ = 0.12
The standard normal variate
z = \(\frac { x-µ }{σ}\) = \(\frac { x-16.28 }{0.12}\) = 1
p(less than 16.35 seconds) = p(x < 16.35)
when x = 16.35
z = \(\frac { 16.35-16.28 }{0.12}\) = \(\frac { 0.07 }{0.12}\) = 0.583
p(x< 16.35) = p(z < 0.583)
= p(—∞ < z < 0) + p(0 < z < 0.583)
= 0.5 + 0.2190
= 0.7190

Question 10.
If the heights of 500 students are normally distributed with mean 68.0 inches and standard deviation 3.0 inches, how many students have height (a) greater than 2 inches (b) less than or equal to 64 inches (c) between 65 and 71 inches.
Solution:
Let x be a normal variate with mean 400 labour days and standard deviation of 100 labour days
m = 400 and σ = 100
The construction work should be completed within 450 days.
The standard normal variate
\(\frac { x-µ }{6}\) = \(\frac { x-400 }{100}\)
personality for 1 labour day = Rs 10,000
If personality amount is = 2,00,000 than No of excess

days = \(\frac { 200000 }{10000}\) = 20
∴ x = 450 + 20 = 470
when x = 470
z = \(\frac { 470-400 }{100}\) = \(\frac { 70 }{100}\) = 0.7
= p(x ≥ 470) = p(z ≥ 0.7)
= 0.5 – 0.2580
= 0.2420

(ii) p(at most 500 days) = p(x ≤ 500 )
when x = 500

z = \(\frac { 500-400 }{100}\) = \(\frac { 100 }{100}\) = 1
p(x ≤ 500) = p(z ≤ 1)
= p(∞ < z < 0) -r- p(0 < z < 1)
= 0.5 + 0.3415
= 0.8413

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 11 Chemical Coordination and Integration Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter Chapter 11 Chemical Coordination and Integration

11th Bio Zoology Guide Chemical Coordination and Integration Text Book Back Questions and Answers

Part I

Question 1.
The maintenance of a constant internal environment is referred as
a) Regulation
b) homeostasis
c) Co-ordination
d) hormonal control
Answer:
b) homeostasis

Question 2.
Which of the following are exclusive endocrine glands?
a) Thymus and testis
b) adrenal and ovary
c) parathyroid and adrenal
d) pancreas and parathyroid
Answer:
c) parathyroid and adrenal

Question 3.
Which of the following hormone is not secreted under the influence of the pituitary gland?
a) thyroxine
b) insulin
c) oestrogen
d) glucocorticoids
Answer:
b) insulin

Question 4.
Spermatogenesis in mammalian testes is controlled by
a) Luteinising hormone
b) Follicle-stimulating Hormone
c) FSH and prolactin
d) GH and prolactin
Answer:
b) Follicle-stimulating Hormone

Question 5.
Serum calcium level is regulated by
a) Thyroxine
b) FSH
c) Pancreas
d) Thyroid and parathyroid
Answer:
d) Thyroid and parathyroid

Question 6.
Iodised salt is essential to prevent
a) rickets
b) scurvy
c) goiter
d) acromegaly
Answer:
c) goiter

Question 7.
Which of the following gland is related to immunity?
a) Pineal gland
b) adrenal gland
c) thymus
d) parathyroid gland
Answer:
c) thymus

Question 8.
Which of the following statement about sex hormones is correct?
a) Testosterone is produced by Leydig ceils under the influence of the luteinizing hormone
b) Progesterone is secreted by corpus luteum and softens pelvic ligaments during childbirth
c) Oestrogen is secreted by both sertoli cells and corpus luteum
d) Progesterone produced by corpus luteum is biologically different from the one produced by the placenta.
Answer:
a) Testosterone is produced by Leydig cells under the influence of luteinizing hormone

Question 9.
Hypersecretion of GH in children leads to
a) Cretinism
b) Gigantism
c) Graves disease
d) Tetany
Answer:
b) Gigantism

Question 10.
A pregnant female delivers a baby who suffers from stunted growth, mental retardation, low intelligence quotient, and abnormal skin. This is the result of
a) Low secretion of growth hormone
b) Cancer of the thyroid gland
c) Over secretion of pars distalis
d) Deficiency of iodine in the diet
Answer:
a) Low secretion of growth hormone

Question 11.
The structure which connects the hypothalamus with the anterior lobe of the pituitary gland is the
a) Dendrites of the neurohypophysis
b) Axons of neuro hypophysis
c) Bands of white fibers from the cerebellar region
d) Hypophysial portal system
Answer:
d) Hypophysial portal system

Question 12.
Comment on homeostasis.
Answer:

• Maintenance of constant internal environment of the body by the different co-ordinating system.
• The maintenance of the constant internal environment of the body is due to the functioning of the endocrine system and nervous system.
  Endocrine gland.

1. a) If the calcium level in the blood decreases the parathyroid gland secretes parathyroid hormones and increases the calcium level in the blood.
b) If there is more calcium in the blood the other hormone secreted by the parathyroid gland called calcitonin acts against the parathormone and reduces calcium level.

2. a) The adrenalin secreted by the adrenal gland in emergency increases heartbeat rate and blood pressure.
b) The other hormone secreted by the adrenal is nor-adrenalin which reduces heartbeat rate and blood pressure.

Nervous system:
1. a) The sympathetic nervous system at the time of shock induces tear glands to secrete tears,
b) The parasympathetic nerve at the time of shock and emotion reduces the tear secretion.

Question 13.
Which one of the following statement is correct
a) Calcitonin and thymosin are thyroid hormones
b) Pepsin and prolactin are secreted in the stomach
c) Secretin and rhodopsin are polypeptide hormones
d) Cortisol and aldosterone are steroid hormones
Answer:
d) Cortisol and aldosterone are steroid hormones

Question 14.
Which of the given option shows all wrong statements for thyroid gland Statements?
i) It inhibits the process of RBC formation
ii) It helps in the maintenance of water and electrolytes
iii) It’s more secretion can reduce blood pressure
iv) It stimulates osteoblast
(a) (i) and (ii)
(b) (iii) and (iv)
(c) (i) and (iv)
(d) (i) and (iii)
Answer:
(d) (i) and (iii)

Question 15.
Hormones are known as a chemical messengers. Justify.
Answer:
Hormones are released into the bloodstream and circulated as chemical signals. These act specifically on certain organs or tissues called target organs or tissues. These speed up or slow down or alter the activity of target tissues or organs. Hence they are known as chemical messengers.

Question 16.
Write the role of t-oestrogen in ovulation.
Answer:

• Oestrogen hormones promote the growth of the ovarian follicle
• While the follicles are growing it secretes the hormone oestrogen which in turn promotes the ovum to develop.
• The shedding up of ovum at the Luteal phase takes place by the influence of the Luteinizing hormone.

Question 17.
Comment on Acini of the thyroid gland.
Answer:
The thyroid gland is a bilobed endocrine gland. Each lobe is made up of many lobules. The lobules consist of follicles called acini. Each acinus is lined with glandular, cuboidal, or squamous epithelial cells. The lumen of the acinus is filled with colloid, a thick glycoprotein mixture consisting of thyroglobulin molecules.

Question 18.
Write the causes for diabetes mellitus and diabetes insipidus.
Answer:

• Diabetes emeritus: If the insulin is not secreted sufficiently the liver and muscles are unable to convert the glucose into glycogen. As a result, more glucose enters into the bloodstream raising the blood sugar level leads to diabetes mellitus.
• Diabetes Insipidus: The hormone antidiuretic hormone is secreted by the neurohypophysis, which promotes reabsorption of water and thus reduces the loss of water through urine ADH deficiency induces the production of large amounts of urine leads to diabetes insipidus.

Question 19.
Specify the symptoms of acromegaly.
Answer:
Acromegaly is caused due to excessive secretion of growth hormone in adults. The symptoms of acromegaly are an overgrowth of hand bones, feet bones, jawbones malfunctioning of gonads. enlargement of viscera, tongue, lungs, heart, liver, spleen, and endocrine glands like thyroid, or adrenal glands.

Question 20.
Write the symptoms of cretinism.
Answer:
Decreased secretion of the thyroid (Hypothyroidism) causes cretinism. The cretins show retarded skeletal growth, absence of sexual maturity retarded mental ability thick wrinkled skin, protruded enlarged tongue bloated face, thick and short limbs occurs. The other symptoms are low BMR slow pulse rate, subnormal body temperature, and elevated blood cholesterol level.

Question 21.
Briefly explain the structure of the thyroid gland.
Answer:
The thyroid gland is butterfly-shaped, bilobed situated below the larynx on each side of the upper trachea. The two lobes are connected by a median tissue mass called isthmus. Each lobe is made up of many lobules. The lobules consist of follicles called acini. Each acinus is lined with glandular, cuboidal, or squamous epithelial cells.

The lumen of acini is filled with colloid, a thick glycoprotein mixture consisting of thyroglobulin molecules. The thyroid gland secretes Tri-iodothyronine (T,) and tetra-iodothyronine (T4) or thyroxine hormones. These are concerned with metabolism.

Question 22.
Name the layers of adrenal cortex and mention their secretions.
Answer:

• The adrenal cortex has three layers namely Zona glomerulosa, Zona fasciculate and Zona reticulate. Zona glomerulosa which constitutes 15% of cortex is a thin outer layer secretes minerals corticoids
• Zona fasciculate the middle widest layer constitutes 75% cortex and secretes gluco corticosteroids such as cortisol, corticosterone and small amount of adrenal androgen and oestrogen.
• Zona reticulata an inner layer of adrenal cortex constitute about 19% of cortex and secretes adrenal androgen and small amount of estrogen and glucocorticoids.

Question 23.
Differentiate hyperglycemia from hypoglycemia.
Answer:
Hyper glycemia:
Hyperglycemia is condition in which there is increased blood glucose level, it may be due to the reduced secretion of insulin.

Hypo glycemia:
Hypoglycemia is a condition in which the blood glucose level decreases. It may be due to increased secretion of insulin there by reducing blood glucose level.

Question 24.
Write the functions of (CCK)- Cholecystokinin.
Answer:
CholecystokininCholecystokinin is secreted by duodenum in response to the presence of fat and acid in the diet. It acts on the gall bladder to release bile into duodenum and stimulates the secretion of pancreatic enzymes and its discharge.

Question 25.
Growth hormone is important for normal growth. Justify the statement.
Answer:
Growth hormone promotes growth of all the tissues and metabolic process of the cell. The growth hormone stimulates the growth in the following ways

• It influences the metabolism of carbohydrate proteins and lipids.
• It increases the rate of protein biosynthesis.
• It stimulates cartilage formation of condrogenesis.
• It stimulates bone formation osteogenesis.
• It helps in the retention of minerals like nitrogen, potassium, phosphorous sodium in the body.
• It increases the release of fatty acid from adipose tissue.
• It decreases the rate of glucose utilization for energy by the cell, by which it conserves glucose for glucose dependent tissues such as the brain.

Question 26.
Pineal gland is an endocrine gland, write its role.
Answer:
The pineal gland or epiphysis cerebri or conarium is located behind the third ventricle of brain. It is formed of paranchymal cells and interstitial cells. It secretes the hormone, melatonin.

It plays a central role in the regulation of circadian rhythm of our body and maintains normal sleep-wake cycle. It also regulates the timing of sexual maturation of gonads. It also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Question 27.
Comment on the functions of adrenalin.
Answer:

• Adrenalin increases liver glycogen breakdown into glucose and increases the release of fatty acids from fat cells.
• During emergency it increases heart beat rate and blood pressure.
• It stimulates the smooth muscles of cutaneous and visceral arteries to decrease blood flow.
• It increases blood flow to the skeletal muscles there by increases the metabolic rate of skeletal muscles cardiac muscles and nervous tissues.

Question 28.
Predict the effects of removal of Pancreas from the human body.
Answer:
Pancreas is both exocrine and endocrine gland. It is located just below the stomach as a leaf like structure. It secretes digestive enzymes and hormones like insulin and glucogon.

The digestive enzymes digest carbohydrates, proteins and fats. Insulin and glucose regulate blood sugar level. If pancreas is removed from the body, digestion and main’taince of blood sugar level gets afftected.

Question 29.
Enumerate the role of kidney as an endocrine gland.
Answer:

• Kidney is a partial endocrine gland. Kidney secretes hormones such as renin, erythropoietin and calcitriol.
• Renin is secreted by Juxta glomerular cells (JG) which increase blood pressure when angiotensin is formed in blood.
• Erythropoietin is also secreted by JGA cells of the kidney and stimulates the formation of RBC in bone marrow known as erythropoiesis.
• Calcitriol is secreated by proximal tubules of nephron, it is an active form of vitamin D3 which promotes calcium and phosphorus absorption from intestine and accelerates bone formation.

Part – II.

11th Bio Zoology Guide Chemical Coordination and Integration Additional Important Questions and Answers

I. Choose The Correct Answer

Question 1.
Where is hormones released ifito?
a) Mouth
b) Blood
c) Digestive system
d) Kidney
Answer:
b) Blood

Question 2.
Find out the endocrine glands from the following.
a) Sebaceous gland
b) Sweat glands
c) Salivary glands
d) Thyroid gland
Answer:
d) Thyroid gland

Question 3.
Which is called as master endocrine glands?
a) Hypothalamus
b) Pituitary gland
c) Thyroid gland
d) Thymus
Answer:
b) Pituitary gland

Question 4.
Where is pituitary situated?
a) On the ethmoid bone
b) On sella turcica
c) On the foramen of Monro
d) On the Rathkes packet
Answer:
b) On sella turcica

Question 5.
The retention of nitrogen is due to this hormone.
a) TSH
b) GH
c) FSH
d) ACTH
Answer:
b) GH

Question 6.
Find out the wrong statement related with growth hormone.
1. a) It stimulates cartilage formation
2. b) It releases the fattyacid from adipose tissue
3. c) It increases the glucose utilization in the cells
4. d) It stimulates the carbohydrate synthesis
Answer:
4. d) It stimulates the carbohydrate synthesis

Question 7.
A male child is born to a parents as he grown if FSH and LH is not properly secreted what happens to the male child.
a) He grows as a normal male child
b) He grows and he shows stunted growth
c) Secondary sexual characters are not developed properly
d) He grows as a mentally depressed male
Answer:
c) Secondary sexual characters are not developed properly

Question 8.
These hormones are collectively known as Gonodotropins?
a) Oxytocin and ADH
b) Oestrogen and Progestron
c) Testosteron and androgens
d) FSH and LH
Answer:
d) FSH and LH

Question 9.
The day and night rhythm is controlled by this hormone.
a) Melonocytes
b) Melanin
c) Melotonin
d) Thyroxine
Answer:
c) Melotonin

Question 10.
Prabhu is working in a MNC Company. He has to do night shift once in every fifteen days.
Aftern a few years he is suffering from sleeplessness (in somnia) What may be the cause of his problem.
a) It may be becauses of his nature of work
b) More work pressure
c) The sleepwake cycle is disturbed due to the irregular synthesis of melotonin hormone
d) Due to the metabolic disturbances
Answer:
c) The sleepwake cycle is disturbed due to the irregular synthesis of melotonin hormone

Question 11.
Name the structure that connects the lobes of thyroid gland?
a) Acinus
b) Ischium
c) Isthmus
d) bridge tissue
Answer:
c) Isthmus

Question 12.
Name the element helps in the synthesis of thyroxine.
a) Iron
b) Calcium
c) Iodine
d) Sodium
Answer:
c) Iodine

Question 13.
Assertion: The Oxyphil cells of parathyroid secrete parathormone
Reason: The chief cells of parathyroid regulates the synthesis of parathormone
a) Assertion and Reason are correct
b) Assertion incorrect and reason is wrong
c) The assertion is true. The reason is false
d) Both the assertion and reason are false.
Answer:
d) Both the assertion and reason are false.

Question 14.
Which of the functional features of hormone is not correctly matched with its description?
a) Thyroid gland hormones often called the major metabolic hormones.
b) Thyro calcitonin increases the blood calcium level
c) The adrenalin is the emergency hormone.
d) The functions of oxyphil cells are not known.
Answer:
b) Thyro calcitonin increases the blood calcium level

Question 15.
Which of the following option shows the with its action matched hormones
(given in column I) (given in column II)

a) A – ii; B – iv; C – i; D – iii
b) A – iv ; B – iii; C – ii; D – i
c) A – iii; B – ii; C – iv; D – i
d) A – iv; B – i; C – iii; D – ii
Answer:
b) A – iv ; B – iii; C – ii; D – i

Question 16.
These are known as supra-renal glands.
a) Thymus gland
b) Pancreas
c) Adrenal gland
d) Ovary
Answer:
c) Adrenal gland

Question 17.
Find out the hormone which are catecholamines.
a) Thyroxine
b) Insulin
c) Adrenalin
d) Glucagon
Answer:
c) Adrenalin

Question 18.
Why there is an accumulation of ketone bodies in blood of diabetic melitus patients?
a) due to the excessive consumption of liquids
b) break down of fat in to glucose
c) conversion of glucose from protein
c) due to excessive in take of food
Answer:
b) break down of fat in to glucose

Question 19.
This hormone promotes the activation of Vitamin D thus by absorbing calcium?
a) Calcitonin
b) Thymosin
c) Parathormone
d) Thyroxine
Answer:
c) Parathormone

Question 20.
Which part of pancreas is act as a exocrine gland?
a) Globules
b) islets of Langerhans
c) Acinus
d) Globlets
Answer:
c) Acinus

Question 21.
Name the cells that secrete somatostatin
a) a cells
b) b cells
c) Lampda cells
d) delta cells
Answer:
d) delta cells

Question 22.
Why is insulin tablet not advisable for chronic diabetic mellitus patients?
a) It takes more time to act
b) The insulin find it difficult to reach the substrate
c) Insulin is easily digested by the digestive enzymes
d) The insulin is not a effective one.
Answer:
c) Insulin is easily digested by the digestive enzymes

Question 23.
This hormone is involved in the cyclic changes of menstruation.
a) Testosterone
b) Pitocin
c) Oestrogen
d) Progesterone
Answer:
c) Oestrogen

Question 24.
Contraction of uterus leads to miscarriages in a pregnant womens.
What would be administered to evacuate the embryo?
a) ADH
b) Vasopressin
c) Androgen
d) Oxytocin
Answer:
d) Oxytocin

Question 25.
In the case of thyrotecdomic patients what is advisable to given along with the thyroxine?
a) Insulin
b) Thyroglobulin
c) Parathormone
d) Adrenalin
Answer:
c) Parathormone

Question 26.
If a doctor finds a high level of atrial natriuretic factor in the blood of a patient what he will suspect?
a) A patient is suffering from in sufficient oxygen supply
b) A patient will have a heart attack due to high blood pressure
c) Suspecting depression problem
d) Many develop thrombosis
Answer:
b) A patient will have a heart attack due to high blood pressure

Question 27.
Name the hormone that stimulates the synthesis of HCl.
a) Enterokinase
b) Pepsinogen
c) Gastrin
d) Secretin
Answer:
c) Gastrin

Question 28.
What is the other name for type I diabetes?
a) Insulin dependent diabetes
b) Non-insulin dependent diabetes
c) Sensitive diabetes
d) Dependent types
Answer:
a) Insulin dependent diabetes

Question 29.
Which is called as second messenger.
a) Receptor cells
b) CAMP
c) Adenylate
d) Substrate
Answer:
b) CAMP

Question 30.
In the following diagram what are the parts A, B, C and D representing?

I) A) Pineal body B) Anterior tube C) Capillary bed D) Infundibulum
II) A) Hypophyseal vein B) Optic chiasma C) Endocrine cells D) Artery
III) A) Infundibuim B) Posterior C) Hypophyseal vein D) Endocrine cells
IV) A) Endocrine cells B) Infundibulum C) Paradisaical D) Pineal body
Answer:
III) A) Infundibuim B) Posterior C) Hypophyseal vein D) Endocrine cells

Question 31.
Find out the true and false statements from the following and on that basis find the correct answer.
i) ADH causes blood vessels to dialate
ii) The ‘c’ cells of thyroid gland secretes calcitonin
iii) Zona fasciculate secretes cortisol
iv) Minerals corticoids regulate water balance
i) a) True b) False c) True
ii) a) False b) True c) False
iii) a) False b) True c) False
iv) a) False b) False c) True
Answer:
iv) a) False b) False c) True

Question 32.
Which part interlinks both the nervous system and endocrine system?
a) Receptor molecules
b) Target tissue
c) Hypothalamus
d) Infundibulum
Answer:
c) Hypothalamus

Question 33.
Which of the following disease is not caused by iodine or thyroxine deficiency?
a) Sporodic goitre
b) Exophthalmic goitre
c) Simple goitre
d) Myxodema
Answer:
a) Sporodic goitre

Question 34.
Which is the correct location of the receptors of the hormones?
a) Extracellular matrix
b) Blood
c) Plasma membrane
d) Nucleus
Answer:
c) Plasma membrane

Question 35.
The primary target of the hormones of hypothalamus is
a) pineal gland
b) thymus
c) testis
d) pituitary
Answer:
d) pituitary

Question 36.
Functionally the adenohypophysis of pituitary gland includes
a) anterior lobe
b) Posterior lobe
c) intermediate lobe
d) both (a) and (c)
Answer:
d) both (a) and (c)

Question 37.
An outgrowth of hypothalamus from the base of the brain develops into
a) pars nervosa
b) pars intermedia
c) pars distalis
d) pars intermedia
Answer:
a) pars nervosa

Question 38.
The hormone secreted by neurohypophysis is
a) ACTH
b) ADH
c) GH
d) TSH
Answer:
b) ADH

Question 39.
Among the following hormones which is the peptide hormone.
a) GH
b) TSH
c) FSH
d) LH
Answer:
a) GH

Question 40.
Among the following which is not a glycoprotein hormone.
a) TSH
b) LTH
c) LH
d) FSH
Answer:
b) LTH

Question 41.
Find out the protein hormone from the following.
a) LTH
b) FSH
c) TSH
d) ACTH
Answer:
a) LTH

Question 42.
Which is the pituitary hormone that is present in other vertebrates?
a) MSH
b) ACTH
c) TSH
d) GH
Answer:
a) MSH

Question 43.
Find out the wrong statement about vasopressin or ADH
a) It promotes re-absorption of water and electrolytes by distal tubules of nephron.
b) Causes constriction of blood vessels
c) It stimulates vigorous contraction of smooth muscles of uterus during child birth
d) It is a peptide hormone
Answer:
c) It stimulates vigorous contraction of smooth muscles of uterus during child birth

Question 44.
The growth hormone releasing hormone stimulates the
a) Thymus to release the hormone
b) Pituitary for synthesis and release of growth hormone
c) Testis to release gonadotropin
d) Adrenal to release growth hormone
Answer:
b) Pituitary for synthesis and release of growth hormone

Question 45.
Posterior pituitary secretion is controlled by
a) hypothalamic hypophyseal portal blood vessel
b) neuro endocrine gland
c) hypophysis
d) hypothalamic hypophyseal axis
Answer:
d) hypothalamic hypophyseal axis

Assertion and Reason:- Directions: In the following questions a statement of Assertion is followed by a statement of reason. Mark the correct choice as;
a) If both Assertion and reason are true and reason is the correct explanation of assertion
b) If both Assertion and reason and true but reason is not the correct explanation of Assertion.
c) If assertion is true but reason is false
d) If both Assertion and reason are false

Question 46.
Assertion: Adrenalin nor-adrenalin, melatonin and thyroid hormones are proteins
Reason: Derived from cholesterol mostly water soluble
Answer:
d) If both Assertion and reason are false

Question 47.
Assertion: Growth hormone stimulates chondrogenesis and osteogenesis
Reason: Growth hormones promote growth of all tissues and metabolic process of the body.
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 48.
Assertion: Adrenal medulla hormones are referred as 3F hormones fight, flight and hormones.
Reason: During emergency it increases heart beat rate and blood pressure
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 49.
Assertion: The effects of aldosterone, oestrogen FSH are long lived as they alter the amount of m- RNA and protein in a cell
Reason: The action of cAMP are terminated by phosphodiesterases
Answer:
b) If both Assertion and reason and true but reason is not the correct explanation of Assertion.

Question 50.
Assertion: The immunity of old age people, becomes week and causes sickness.
Reason: Due to degeneration of pineal gland thymosin level decreases
Answer:
c) If assertion is true but reason is false

Question 51.
Assertion: JGA cells of the kidney stimulates erythropoiesis or formation of RBC
Reason: JGA cells also secrete Erythropoietin
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 52.
Assertion: Diabetes inspidus is marked by production of large amount of urine.
Reason: Hypo secretion of ADH leads to a condition of reduced water absorption. Thus the urine becomes diluted without sugar or glucose
Answer:
a) If both Assertion and reason are true and reason is the correct explanation of assertion

Question 53.
The Luteinizing hormone in males is
a) Testosterone
b) ICSH
c) FSH
d) LTH
Answer:
b) ICSH

Question 54.
The cells that secrete parathyroid hormone is knows as
a) chief cells
b) oxyphil cells
c) goblet
d) both b and c cells
Answer:
a) chief cells

Question 55.
Find out the correct statement about pineal gland.
a) Stimulates the production and release of sperms.
b) Increases blood pressure.
c) It plays a central role and the regulation of circadian rhythm of our body and maintains the normal sleep wake cycle.
d) It is about 1cm in diameter and 0.5gm.
Answer:
c) It plays a central role and the regulation of circadian rhythm of our body and maintains the normal sleep wake cycle.

Question 56.
The BMR is regulated by
a) Parathormone
b) Thyrocalcitonin
c) Adrenalin
d) Thyroxine
Answer:
d) Thyroxine

Question 57.
The primary function of thymus gland is
a) regulation of body temperature
b) regulation of body growth
c) immunological functions
d) Secretion of thyrotropin
Answer:
c) immunological functions

Question 58.
A hormone secreted by adrenal gland and called life-saving hormone is
a) adrenaline
b) cortisone
c) aldosterone
d) Cortisol
Answer:
d) Cortisol

Question 59.
Which of the following condition is not linked to a deficiency of thyroid hormone?
a) cretinism
b) goitre
c) Myxoedema
d) Exophthalmia
Answer:
d) Exophthalmia

Question 60.
Androgens are sex corticoids secreted from
a) Zona reticulate
b) Adrenal medulla
c) Zona glomerulosa
d) Acini
Answer:
a) Zona reticulate

Question 61.
A gland which is well developed in newborn child and produce lymphocytes
a) Thyroid gland
b) Thymus
c) Parathyroid gland
d) Pineal gland
Answer:
b) Thymus

Question 62.
Which one reduces the blood calcium level and shows an opposite effect to parathormone?
a) ADH
b) Insulin
c) Thyrocalcitonin
d) Thyroxine
Answer:
c) Thyrocalcitonin

Question 63.
Secretion of HCl and pepsinogen is controlled by
a) Cholecystokinin
b) Gastrin
c) Calcitriol
d) Renin
Answer:
b) Gastrin

Question 64.
A man has an IQ equivalent to that of a boy 5 years old this is due to the deficiency of which hormone?
a) Thyroxine
b) Adrenaline
c) Aldosterone
d) Somatotropin
Answer:
a) Thyroxine

Question 65.
Which of the following option shows the correct matching of disorder’s and causes.
A) Addison’s disease -(i) Hypo secretion of thyroid
B) Cushing’s syndrome – (ii) Hyper secretion of parathyroid hormone
C) Softening of bone – (iii) Hypo secretion of gluco corticoids
D) Gull’s disease (in adults) – (iv) Excess secretion of cortisol
Codes:
a) A – (ii); B – (i); C – (iii); D – (iv)
b) A – (iii); B – (iv); C – (ii); D – (i)
c) A – (iii); B – (ii); C – (i); D – (iv)
d) A – (iv); B – (iii); C – (iv); D – (ii)
Answer:
b) A – (iii); B – (iv); C – (ii); D – (i)

Question 66.
A person is having problems with calcium and phosphorous metabolism in his body.
Which one of the following glands may not be functioning.
a) Parathyroid
c) Pancreas
b) Parotid
d) Thyroid
Answer:
a) Parathyroid

Question 67.
Presence of fat and acid in the diet induces the secretion of
a) Gastrin
b) Secretion
c) Cholecystokinin
d) Calcitrol
Answer:
c) Cholecystokinin

Question 68.
Which is an amino acid derivative hormone?
a) Epinephrine
c) Progesterone
b) Oestrogen
d) Relaxin
Answer:
a) Epinephrine

Question 69.
Which of the following is a mineralococticoid?
a) Testosterone
b) Cortisol
c) Adrenalin
d) Aldosterone
Answer:
d) Aldosterone

Question 70.
Which hormone increases the rate of protein biosynthesis chondrogenesis and osteogenesis and helps in the retention of minerals?
a) Prolactin
b) Somatotrophic hormone
c) Thyrotropin
d) Glucagon
Answer:
b) Somatotrophic hormone

Question 71.
The male sex hormones are secreted by
a) Zona glomerulosa
b) Fat cells
c) Lay-dig cells
d) Acini
Answer:
c) Lay-dig cells

Question 72.
Which of the following pituitary hormone is secreted without the involvement of a releasing hormone?
a) Thyrotropin
b) Follicle stimulating hormone
c) Oxytocin
d) Prolactin
Answer:
c) Oxytocin

Question 73.
Match the following columns.

Code:

Answer:
b) A -3,B-1,C-4,D-2

Question 74.
Which hormones can easily pass through the cell membrane and bind to their receptors and alter gene function?
a) Peptide hormones
b) Amino acid derived hormones
c) Neuro hormones
d) Steroid hormones
Answer:
d) Steroid hormones

Question 75.
The hormone which helps to find out conception is
a) FSH
b) Oestrogen
c) HCG
d) LH
Answer:
c) HCG

Question 76.
Gigantism and Acromegaly are due to
a) Hypothyroidism
b) Hyperthyroidism
c) Hypopituitarism
d) Hyper pitituitarism
Answer:
d) Hyper pitituitarism

Question 77.
After performing the functions in the target organs how hormones are inactivated and excreted?
a) By intestine
b) By lungs and skin
c) By liver and Kidney
d) Both a and b
Answer:
c) By liver and Kidney

Question 78.
The half life period of insulin is
a) 6 minutes
b) 8 minutes
c) 15 minutes
d) 7 minutes
Answer:
a) 6 minutes

Question 79.
The time taken by insulin to be cleared from circulation is
a) 10 -20 minutes
b) 10-15 minutes
c) 5 – 10 minutes
d) 2-10 minutes
Answer:
b) 10-15 minutes

(2 Marks)

II. Very Short Answer.

Question 1.
What is the causes of bone cyst formation?
Answer:
Hyper para thyrodism causes demineralisation of bone causes bone cyst makes the bone fragile and soft.

Question 2.
Why is the hypothalamus considered a neuroendocrine gland?
Answer:
The hypothalamus alone with its neural function produces hormones. Hence it is considered a neuroendocrine gland.

Question 3.
What is the meaning of the word hormone?
Answer:
Hormone means to excite.

Question 4.
Write on the origin of the pituitary gland?
Answer:
The anterior lobe of the pituitary gland originates from the embryonic invagination of the pharyngeal epithelium called Rathke’s pouch. The posterior lobe originates from the base of the brain as an outgrowth of the hypothalamus.

Question 5.
What is meant by Homeostasis?
Answer:
Maintenance of constant internal environment of the body by the different co-ordinating system is homeostasis.

Question 6.
What is Pars nervosa?
Answer:
The neurohypophysis of the pituitary gland is known as pars nervosa.

Question 7.
Give example for partial endocrine glands.
Answer:
Pancreas, gastrointestinal tract epithelium kidney, heart gonads and placenta.

Question 8.
Write a paragraph on the Growth Hormone?
Answer:
Growth hormone (GH):
It is also known as somatotropic hormone (STH) or Somatotropin. It is a peptide hormone Growth hormone promotes the growth of all the tissues and metabolic processes of the body. It influences the metabolism of carbohydrates, proteins, and lipids and increases the rate of protein biosynthesis in the cells.

It stimulates chondrogenesis (cartilage formation), osteogenesis (bone formation) and helps in the retention of minerals like nitrogen, potassium, phosphorus, sodium, etc., in the body. GH increases the release of fatty acid from adipose tissue and decreases the rate of glucose utilization for energy by the cells. Thus it conserves glucose for glucose-dependent tissues, such as the brain.

Question 9.
Name the hormone of peptide nature?
Answer:
Insulin, glucagon and pituitary hormone which are water soluble.

Question 10.
What are steroid hormones.
Answer:
They are derived from cholesterol and are lipid soluble.
Ex. Cortisol aldosterone testosterone oestrogen progesterone.

Question 11.
What is the role of Follicle stimulating hormone in man?
Answer:
In male FSH acts on the germinal epithelium of semi niferous tubules and stimulates the production and release of sperms.

Question 12.
What is the function of LH in female?
Answer:
LH induces ovulation maintains the corpus luteum and promotes the synthesis and release of ovarian hormones.

Question 13.
Why there is a short life span for hormone-like insulin?
Answer:
Insulin hormone is usually short lived as it has to work through second messenger (cAMP) system.

Question 14.
Why the hormones steroid may be long-lived?
Answer:
The effect of steroid hormones are long lived as they alter the amount of mRNA and protein in a cell.
Ex. Aldosterone oestrogen FSH.

Question 15.
How do the hormones reach and act on the specific target organs?
Answer:

• The hormones are released into the blood and circulated as chemical signals
• The target organs contain receptor molecules either on the surface or within the cell.
• The cells that contain the receptor molecules specific for the hormone are physiologically activated.
• Where as other hormones that come in contact can not be activated.

Question 16.
Name the three zones which are present in the Adrenal gland.
Answer:

1. Zona glomerulosa
2. Zona fasciculata
3. Zona reticularis

Question 17.
Differentiate amines and steroid hormones
Answer:

Question 18.
Differentiate exocrine glands from endocrine glands.
Answer:

Question 19.
How endocrine glands be classified based on their secretary function?
Answer:

• Exclusive endocrine glands, e.g. Pituitary thyroid, Parathyroid, Pineal, Adrenal
• Neuro endocrine gland – Hypothalamus
• Partial endocrine glands, e.g. Pancreas, gastro intestinal tract epithelium, kidney, heart gonads and placenta – have endocrine tissues.

Question 20.
Pituitary gland is known as master endocrine glands. Justify the statement.
Answer:

• Pituitary gland is known as master endocrine gland, but it is in turn controlled by the hypothalamus and so the statement may not be totally applicable.
• The hypothalamus with its neuro secretary cells produces neuro transmitters which regulate the secretions of the pituitary.

Question 21.
Write about the location and dimension of pituitary gland.
Answer:

• The pituitary gland is located in the bony cavity of the sphenoid bone the sella tursica at the base of brain so is also called hypothalamus cerebri
• it is about one centimeter in diameter and 0.5gm in weight.

Question 22.
What is infundibulum?
Answer:
The pituitary gland is connected to the hypothalamic region of the brain by a stalk called infundibulum.

Question 23.
What is Rathke’s pouch?
Answer:
The anterior lobe of pituitary originates the embryonic invagination of pharyngeal epithelium called Rathke’s pouch.

Question 24.
Comment on MSH or Melanocyte stimulating hormone.
Answer:

• In mammals role of Pass intermedia is insignificant.
• In other vertebrates pass intermedia secretes melanocyte stimulating hormone or MSH.
• It induces pigmentation in the skin.

Question 25.
What are the functions of pineal gland?
Answer:
In human, the pineal gland or epiphysis cerebri or conarium is located behind the third ventricle of brain and is formed of parenchymal cells and interstitial cells.

It secretes the hormone, melatonin, which plays a central role in the regulation of circadian rhythm of our body and maintains the normal sleep-wake cycle. It also regulates the timing of sexual maturation of gonads. In addition, melatonin also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Question 26.
What are the other names of Luteotropic hormone?
Answer:

1. Luteotropin
2. Lactogenic hormone
3. Proloctein
4. Mammotropin

Question 27.
Name the hormones that their secretions are regulated by negative feed back mechanisms?
Answer:

• Thyroid stimulating hormone TSH or Thyrotropin
• Adreno corticotropic hormone or ACTH

Question 28.
Give the meanings of the word pituitary oxytocin and Hormone?
Answer:

1. Pituitary means “to grow under”.
2. Oxytocin means “quick birth”.
3. Hormone means “to excite”.

Question 29.
Mention the importance of Luteotropic hormone in females?
Answer:
It stimulates milk secretion after the child birth.

Question 30.
Why prolactin is called luteotropic hormone?
Answer:

• High prolactin secretion during lactation
• Since it induces the corpus luteum hence named as luteotropic hormone.

Question 31.
Point out the role of oxytocin in females?
Answer:

• It stimulates vigorous contraction of the smooth muscles of uterus during child birth.
• Ejection of milk from the mammary glands after child birth.

Question 32.
Name the hormones that play a key role in milk secretion?
Answer:

• Prolactin or lactogenic hormone or mammotropin or luteotropic hormone.
• Oxytocin.

Question 33.
Name the hormone of pituitary that act on bloodvessels?
Answer:
The vasopressin causes constriction of blood vessels when released in large amount and in-creases blood pressure.

Question 34.
Which gland is located behind the third ventricle of brain?
Answer:
The pineal gland or epiphysis cerebri or conarium.

Question 35.
Which is the largest endocrine in the body and where it is located?
Answer:

• The thyroid gland is the largest gland.
• It is a bibbed gland located below the larynx on each side of upper trachea.

Question 36.
Name the hormones secreted by thyroid gland.
Answer:

• Tri-iodo thyronine or T3
• Tetra-iodo thyromne or T4 or Thyroxine
• Thyrocalcitonin

Question 37.
What are parafollicular cells or ‘C’ cells?
Answer:

• These are the cells in the thyroid gland.
• These cells secrete a hormone called thyrocalcitonin.

Question 38.
What element is important for synthesis of thyroid hormones? In what quantity it is essential?
Answer:

• Iodine is essential for the normal synthesis of thyroid hormones.
• About 1m. a week of Iodine is required.

Question 39.
Mention the normal glucose level in prepandial and postpandial test for glucose?
Answer:

1. Prepandial- 70-100 mg/dl (Fasting)
2. Post pandial (About 2 hours after food) – 110 – 140mg/ dl.

Question 40.
Is it advisable to take alcohol frequently? What ill effects does it cause over the body?
Answer:

• Alcohol consumption has widespread effect on endocrine system.
• It impairs the regulation of blood glucose level.
• More over it reduces the testosterone level
• Increases the risk of osteoporosis.

Question 41.
What is the injection administered to diabetic patients? Why is it given as injection and not as oral pills?
Answer:

• Humiline-N is administered to diabetic patients.
• Human insulin is administered as injection and not by oral consumption.
• The reason is if it is administered by oral consumption it may be digested by digestive enzymes.

Question 42.
What is sporadic goiter?
Answer:

• It is a genetic disease
• It is not caused by iodine or thyroxine deficiency.

Question 43.
Why laughing is good for health?
Answer:
It reduces the secretion of stress hormone, adrenalin and makes us to relax.

Question 44.
Define circadian rhythm.
Answer:
It is the 24-hour cycle of biological activities associated with natural periods of light and darkness.
Eg. Sleep wake cycle, body temperature, appetite etc.

(3 Marks)

III. Short Answer

Question 1.
What is simple goiter? What are its symptoms?
Answer:

• Simple goitre is otherwise known as endemic goitre.
• It is due to the hypo secretion of thyroxine.
• The symptoms are Enlargement of thyroid gland, Fall in serum thyroxine level, Increased TSH secretion.

Question 2.
What is tetany?
Answer:

• The hyposecretion of parathyroid hormones leads to a decrease in calcium level and increase in phosphate level, it causes.
• convulsion in muscle, locking of jaws, increased heart beat rate increased body temperature muscular spasm lead to tetany.

Question 3.
What is cushing’s syndrome? What are its symptoms?
Answer:
The excess secretion of cortisol causes cushing’s syndrome. The symptoms are obesity of the face and trunk.

1. Redness of face hand and feet.
2. Thick skin.
3. Excessive hair growth
4. Loss of mineral from bone
5. Systolic hypertension

Question 4.
What is the cause of dwarfism?
Answer:
It is due to the hypo-secretion of growth hormone in children in which skeletal growth and sexual maturity is arrested. They attain a maximum height of 4 feet only.

Question 5.
What is Gigantism?
Answer:

• Due to the hyper-secretion of growth hormone in children there is a over growth of skeletal
• structure may occur up to 8 feet height. The visceral growth is not appropriate with that of limbs.

Question 6.
You are walking on the road, suddenly a man with a knife in his hand comes in front of you. What would be your reaction?
Answer:
I will get bimple goose due to the Surge of vasodielation on the arector pili muscle and though, i am very much frightened, i will fight with that man. i will get that energy by the action of the hormone adrenalin.

Question 7.
Why oxytocin is considered as quick or rapid birth?
Answer:
Oxytocin stimulates the contraction of the smooth muscles of uterus during child birth which helps in the expulsion of foetus, hence it is called as quick birth.

Question 8.
Why thymus is considered as a lymphoid organ?
Answer:
Thy lymphocytes that comes to thymus is educated to become immuno competent T lymphocytes and provides cell mediated immunity. Hence thymus is a lymphoid organ.

Question 9.
Why is gluco corticoids considered in the life saving activity?
Answer:
During the period of emergency the gluco corticoids stimulate the synthesis of glucose from lipid and protein by lipolysis and proteolysis and releases energy to meet that emergency situation.

Question 10.
Why cortisol works as a stress combat hormone?
Answer:

• Cortisone involved in maintaining cardio vascular and kidney functions. It produces anti inflammatory reactions and suppresses the immune response, it stimulates the RBC production.
• Hence it is known as stress combat hormone.

Question 11.
How do the hormones act in the target tissue?
Answer:

• The hormones are released into the blood and circulated as chemical signals and act on specific target organs.
• Hormones may speed up or slow down or alter the activity of the target organs.
• The hormones secreted do not remain permanently in the blood.
• They are converted by the liver into inactive compound and excreted by kidneys.

Question 12.
What is a limbic system?
Answer:

• It is a collection of special structures located in the middle of the brain.
• It is also known as paleo mammalian brain.
• It controls emotions, behavior, motivation of long term memory and olfaction.

Question 13.
What are exocrine glands? Give examples
Answer:

• The exocrine glands have ducts to carry their secretion to the membrane surfaces.
• They secrete enzymes, saliva arid sweat.
• Examples are salivary gland, gastric gland.

Question 14.
Write down the functions of hypothalamus.
Answer:

1. Hypothalamic hormones control anterior pituitary secretion through hypothalamic hypophyseal portal blood vessel.
2. The nerve signal produced by the hypothalamic hypophyseal axis control the posterior pituitary secretion.
3. Hypothalamus maintains homeostasis.
4. Blood pressure
5. Body temperature.
6. Cardio and fluid electrolyte balance of the
7. As the part of limbic system it influences various emotional responses.

Question 15.
Draw the diagram of the hypothalamus and pituitary gland and label the following parts.
Answer:
A. Anterior lobe
B. Posterior lobe
C. Hypothalamus
D. Interior Hypophyseal artery
E. Endocrine cells
F. Hypophyseal vein

Question 16.
Draw the diagram of thyroid gland and label the following parts
Answer:
A Thyroid cartilage
B. Thyroid gland
C. Trachea
D.Isthumus

Question 17.
Draw the diagram of thyroid gland and label the following parts
A. Capsule
B. Cortex
C. Medulla
D. Blood Vessels

Question 18.
Explain the role of leuteinizing hormone (LH) in male and females.
Answer:

• It is a glycoprotein hormone
• It is also known as Interstitial cell stimulating hormone (ICSH) in males.
• The ICSH hormones acts on the interstitial cells of testis to produce the male sex hormone testosterone.
• In females along with FSH matures the ovarian follicles.
• LH independently induces ovulation, maintains the corpus luteum and promotes synthesis and release of ovarian.
• FSH and LH secretion starts only during pre pubertal period.
• FSH and LH are collectively referred as gonadotropins.

Question 19.
Compare the structural difference of vasopressin and oxytocin. Vasopressin Oxytocin
Answer:

Question 20.
How does the posterior lobe of the pituitary help in osmoregulation?
Answer:

• ADH is a peptide hormone
• It promotes absorption of water and electrolytes by distal tubules of nephron and there by reduces loss of water through urine.
• Hence it is called as anti diuretic hormone.
• ADH deficiency causes Diabetes insipidus which induces the production of large amount of urine.
• This is how it helps in osmoregulation.
• ADH when released in large amount causes constriction of blood vessels and increases blood pressure.

Question 21.
Explain the role of melatonin in our body.
Answer:

• It is secreted by pineal gland.
• It plays a central role in the regulation of circadium rhythm of our body
• Maintains the normal sleep wake cycle.
• It also regulates the timing of sexual maturation of gonads.
• In addition it also influences metabolism, pigmentation, menstrual cycle and defence mechanism of our body.

Question 22.
List out the role of thyroxine or tetra iodo thyronine (T4) in our body.
Answer:

• It regulates the Basal Metabolic Rate (BMR) and body heat production.
• It stimulates protein synthesis and promotes growth
• It is essential for the development of skeletal and nervous system.
• It plays an important role in maintaining blood pressure
• It reduces serum cholesterol levels.
• Optimum levels of thyroxine in the blood are necessary for gonadial functions.

Question 23.
Which hormone is called hypercalcemic hormone? Explain its role.
Answer:

• The parathyroid hormone (PTH) is the hypercalcemic hormone.
• It is a peptide hormone.
• It involves in controlling the calcium and phosphate homeostasis.
• The secretes or PTH is controlled by calcium level in the blood.
• It increases the blood calcium level by stimulating osteoclasts to dissolve the bone matrix.
• As a result calcium and phosphate are released into the blood.
• PTH enhances the re-absorption of calcium and exertion of phosphates by the renal tubules.
• It promotes activation of vitamin D to increase calcium absorption by intestinal mucosal cells.

Question 24.
Explain the role of heart as a partial endocrine gland.
Answer:
1. In the heart, cardiocytes on the atrial walls secretes an important peptide hormone called Atrial Natriuretic Factor (ANF)
2. When blood pressure is increased ANF is secreted and causes dilation of the blood vessels to reduce the blood pressure.

Question 25.
Is it good to take synthetic soft drinks? Why?
Answer:

• It is not good to take synthetic soft drinks.
• The branded soft drinks damage our endocrine system.
• While consuming soft drinks the sugar level increases in blood. Which leads to elevated insulin secretion
  to reduce the blood glucose level.
• The elevated insulin level diminishes immunity.
• It causes obesity, cardio-vascular disorders etc.