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Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 7 Probability Distributions Ex 7.1 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 7 Probability Distributions Ex 7.1

Question 1.
Define Biomial distribution.
Solution:
Binomial distribution was discovered by James Bernoulli (1654-1705) in the year 1700.
A random variable X is said to follow binomial distribution with parameter n and p, if it assumes only non-negative value and its probability mass function in given by

Question 2.
Define Bernouli trials.
Solution:
A random experiment whose outcomes are of two types namely success S and failure F, occurring with probabilities p and q respectively, is called a Bernoulli trial.
Some examples of Bernoulli trials are:
(i) Tossing of a coin (Head or tail)
(ii) Throwing of a die (getting even or odd number)

Question 3.
Derive the mean and variance of bionomial distribution
Solution:
Derivation of the Mean and Variance of Binomial distribution:
The mean of the binomial distribution

= np(q + p)n – 1 [since p + q = 1]
= np
E(X) = np
The mean of the binomial distribution is np.
Var(X) = E(X²) – E(X²)

= n(n – 1)p²(q + p)(n – 2) + np
n(n – 1 )p² + np
Variance = E(X²) – [E(X)]²
= n²p² – np² + np – n²p²
= np(1 – p) = npq
Hence, mean of the BD is np and the Variance is npq.

Question 4.
Write down the condition for which the bionomial distribution can be used.
Solution:
The Binomial distribution can be used under the following conditions:
1. The number of trials ‘n finite
2. The trials are independent of each other.
3. The probability of success ‘p’ is constant for each trial.
4. In every trial there are only two possible outcomes – success or failure.

Question 5.
Mention the properties of bionomial distribution.
Solution:
Properties of Binomial distribution
1. Binomial distribution is symmetrical if p = q = 0.5, It is skew symmetric if p ≠ q. It is positively skewed if p < 0.5 and it is negatively skewed it p > 0.5.
2. For Binomial distribution, variance is less than mean
Variance npq = (np) q < np

Question 6.
If 5% of the items produced turn out to be defective, then find out the probability that out of 10 items selected at random there are
(i) exactly three defectives
(ii) atleast two defectives
(iii) exactly 4 defectives
(iv) find the mean and variance.
Solution:
Probability of getting a defective item

In binomial distribution
p(X = x) = nC_xp^xq^n-x

Let x = (19)²
log x = 7 log(19)⁷
= 7 log 19
= 7 × 1.2788
= 8.9516
x = Antilog 8.956
= 8.945 × 10⁸
ut y = (20)¹⁰
log y = (10) log 20
= 10 × 1.3010
= 13.010
y = Anti log 13.010
= 1.023 × 10³

(ii) p(atleast two defectives)
= p(x ≥ 2)
= p(x = 2) = p(x = 3) + ………….. + p(x = 10)
= 1 – p(x < 2)
= 1 – {p(x = 0) + p(x = 1)}

Let x = (19)⁹
log x = 9 log 19
= 9 × 1.2788
= 11.5092
x = Antilog 11.5092
= 3.229 × 1011

(iii) p(extactly 4 defectives) = p(X = 4)

Let x = (19)⁶
log x = 6 log 19
= 6 × 1.2788
log x = 7.66728
Antilog (7.66728)
x = 4.648 × 10⁷

(iv) mean E(x) = np
= 10 × \(\frac { 1 }{20}\) = \(\frac { 1 }{2}\) = 0.5
Varaince = npq
= 10 × \(\frac { 1 }{20}\) = \(\frac { 19 }{20}\) = \(\frac { 19 }{40}\) = 0.475

Question 7.
In a particular university 40% of the students are having news paper reading habit. Nine university students are selected to find their views on reading habit. Find the probability that
(i) none of those selected have news paper reading habit
(ii) all those selected have news paper reading habit
(iii) atleast two third have news paper reading habit.
Solution:
let p to the probability of having newspaper reading habit
p = \(\frac { 40 }{100}\) = \(\frac { 2 }{5}\)
q = 1 – p = 1\(\frac { 2 }{5}\) = \(\frac { 5-2 }{5}\) = \(\frac { 3 }{5}\) and n = 9
In the binomial distribution p(x = 4) = nc_x p^xq^n-r
The binomial distribution P(x) = 9c_x (\(\frac { 2 }{5}\))^x (\(\frac { 3 }{5}\))^9-x

(i) p(none of those selected have newspaper reading

(ii) P(all those selected have newspaper reading habit)

(iii) p(at least two third have newspaper reading habit)

Question 8.
In a family of 3 children, what is the probability that there will be exactly 2 girls?
Solution:
let p be the probability of getting a girl child= 1/2 q = 1 – p ⇒ = 1 – 1/2
∴ q = \(\frac { 1 }{2}\) and n = 3
In a binomial distibution
p(x = x) nc_x p^xq^n-x
p(exactly 2 girls) p(x = 2)

Question 9.
Defects in yarn manufactured by a local mill can be approximated by a distribution with a mean of 1.2 defects for every 6 metres of length. If lengths of 6 metres are to be inspected, find the probability of less than 2 defects.
Solution:
Given n = 6
mean np = 1.2
⇒ 6p = 1.2
p = \(\frac { 1.2 }{6}\) p = 0.2 (or) p = \(\frac { 1 }{5}\)
q = 1 – p = 1 – \(\frac { 1 }{5}\)
∴ q = \(\frac { 4 }{5}\)
The binomial distribution
p(x) = 6C_x (0.2)^x(0.8)^6-x
p(x < 2) = p(x = 0) + p(x = 1)

Question 10.
If 18% of the bolts produced by a machine are defective, determine the probability that out of the 4 bolts chosen at random
Solution:
n = 4
probability of defective bolts p = 18/100
9 = 1 – p = 1.018 = 0.82
The binoial distribution p(x) = 4C_x(0.18)^x(0.82)^4-x
= 4C₁(0.18)¹(0.82)^4-1
= 4 × 0.18 × (0.82)³
= 0.72 × 0.551368
= 0.39698496
p(X = 1)= 0.3969 approximately

(ii) p(none will be defective)p(x = 0)
= 4C₀(0.18)°(0.82)^4-0
= (1)(1)(0.45212176)
p(x = 0) = 0.45212

(iii) p(almost 2 will be defective) = p(x ≤ 2)
= p(x = 0) + (p(x = 1) + p(x = 2)
= 4C₀(0.18)°(0.82)^4-0 + 4C₁(0.18)₁(0.82)^4-1 + 4C₂ (0.18)² (0.82)^4-2
= (0.82)⁴ + 4 × (0.18) × (0.82)³ + \(\frac { 4×3 }{1×2}\) × (0.18)² (0.82)²
= 0.45212176 + (0.72 × 0.551368) + (6 × 0.0324 × 0.6724)
= 0.45212176 + 0.39698496 + 013071456
= 0.97982128
= 0.9798

Question 11.
If 18% of the bolts produced by a machine are defective, determine the probability that out of the 4 bolts chosen at random
(i) exactly one will be defective
(ii) none will be defective
(iii) atmost 2 will be defective
Solution:
p = 0.09 = \(\frac { 9 }{100}\)
q = 1 – p ⇒ q – 1 – \(\frac { 9 }{100}\)
q = \(\frac { 100-9 }{100}\)
q = \(\frac { 91 }{100}\)
In a binomial distribution p(x = x) = nc_xp^xq^n-x
p(atleast one success) = p(x ≥ 1)

Taking log on both sides log ≤ (0.66) ≤ n log(0.91)
∴ n ≥ log \(\frac { log(0.66) }{log(0.91)}\)
n ≥ 5
∴ 5 or more trials are needed

Question 12.
Among 28 professors of a certain department, 18 drive foreign cars and 10 drive local made cars. If 5 of these professors are selected at random, what is the probability that atleast 3 of them drive foreign cars?
Solution:
Let p be the probability of foreign cars driven by the professors
p = \(\frac { 18 }{28}\) = \(\frac { 9 }{14}\)
Let q be the probability of local made cars driv¬en by the professors
q = \(\frac { 10 }{28}\) = \(\frac { 5 }{14}\)
and n = 5
The binomial distribution p(x = x) = nc_xp^xq^n-x

Question 13.
Out of 750 families with 4 children each, how many families would be expected to have (i) atleast one boy (ii) atmost 2 girls (iii) and children of both sexes? Assume equal probabilities for boys and girls?
Solution:
Assume equal probabilities for boys girls let p be the probability of having a boy Let x be the random variable for getting either a boy or a girl
∴ p = \(\frac { 1 }{2}\) and q \(\frac { 1 }{2}\) and n = 4
In binomial distribution p(x = 4) = nc_xp^xq^n-x
Here the binomial distribution is p(X= x)

= 1 – 0.0625
= 0.9375
for 750 families (p ≥ 1) = 750 × 0.9375
= 703.125
= 703(approximately)

(ii) p(almost 2 girls) = p(x ≤ 2)
= p(x = 0) = p(x = 1) + p(x = 2)

For 750 families p(x ≤ 2) = 0.6875 × 750
= 515.625
= 516 (approximately)

(iii) p(children of both sexes) = p(x = 1) + p(x = 2)p(x = 3)

= 0.875 x 750
For 750 families p(x = 2) = 0.875 × 750
= 656.25
= 656 (approximately)

Question 14.
Forty percent of business travellers carry a laptop. In a sample of 15 business travelers,
Solution:
Given n = 5
p = \(\frac { 40 }{100}\) = \(\frac { 2 }{5}\)
q = 1 – p = 1 – \(\frac { 2 }{5}\) \(\frac { 5-2 }{5}\) = \(\frac { 3 }{5}\)
The binomial distributionp (X = x) = 15c_x (\(\frac { 2 }{5}\))^x (\(\frac { 3 }{5}\))^15-x
(i) p(probability that 3 will have a laptop) = p(x = 3)

(ii) p(12 of the traels will not have a laptop)
= 1 – p(x = 12)
= 1 – 15c₁₂ (\(\frac { 2 }{5}\))¹² (\(\frac { 3 }{5}\))^15-12

(iii) p(at least three of the travelers have a laptop)
= p(x ≥ 3)
p(x ≥ 3) = 1 – p (x < 3)
= 1 – [p(x = 0) + p(x = 1) + p(x = 2)]
p(x < 3) = p(x = 0) + p(x = 1) + p(x = 2)

Question 15.
A pair 5f dice is thrown 4 times. If getting a doublet is considered a success, find the probability of 2 successes.
Solution:
In a throw of a pair dice the doublets are (1, 1),(1, 2) (3, 3),(4, 4),(5, 5),(6, 6)
probability of getting a doublet p = \(\frac { 6 }{36}\) = \(\frac { 1 }{6}\)
⇒ q = 1 – q = \(\frac { 5 }{6}\) and n = 4 is given
The probability of success = \(\left[\begin{array}{l}
4 \\
x
\end{array}\right]\) [latex]\frac { 1 }{6}[/latex]^x [latex]\frac { 5 }{6}[/latex]^4-x
Therefore the probability of 2 success are

Question 16.
The mean of a binomial distribution is 5 and standard deviation is 2. Determine the distribution.
Solution:
In a binomial distribution
mean np = 5 → (1)
Standard deviation \(\sqrt { npq}\) = 2
squaring on body sides
npq = 4 → (2)

n = 5 × 5 ⇒ n = 25
∴ the binomial distribution is
P(X = x) = nc_xp^xq^n-x
(i.e) p(X = x) = \(\left[\begin{array}{l}
25 \\
x
\end{array}\right]\) (\(\frac { 1 }{5}\))^x (\(\frac { 4 }{5}\))^(25-x)

Question 17.
Determine the binomial distribution for which the mean is 4 and variance 3. Also find P(X = 15)
Solution:
In a binomial distribution
mean np = 4 → (1)
variance npq = 3 → (2)

n = 4 × 4 ⇒ n = 16
The binomial distribution is p(X = x)nc_xp^xq^n-x

Question 18.
Assume that a drug causes a serious side effect at a rate of three patients per one hundred. What is the probability that atleast one person will have side effects in a random sample of ten patients taking the drug?
Solution:
Here n = 10

= 0.5344

Question 19.
Consider five mice from the same litter, all suffering from Vitamin A deficiency. They are fed a certain dose of carrots. The positive reaction means recovery from the disease.
Assume that the probability of recovery is 0.73. What is the probability that atleast 3 of the 5 mice recover.
Solution:
n = 5
Let probability of recovery p = 0.73
q = 1 – p = 1 – 0.73
∴ q = 0.27
The binomial distribution is
p (x = x) = nC_xp^xq^n-x
p(x = x) = 5C_x(0.73)^x(0.27)^5-x
p(atleast 3 of the 5 mice recover) = p(x ≥ 3)
= p(x = 3) + p(x = 4) + p(x = 5)
= 5C₃ (0.73)³(0.27)^5-3 + 5C₄ (0.73)⁴ (0.27)^5-4 + 5C₅ (0.73)⁵ (0.27)^5-5
5C₂ (0.73)³ (0.27)² + 5c₁ (0.73)⁴ (0.27)¹ + 5c₀(0.73)⁵(0.27)°
[\(\frac { 5×4 }{1×2}\) × 0.389017 × 0.0729] + [5 × 0.28398241 × 0.27] + (1 × 0.2073071593 × 1)
= 0.283593393 + 0.3833762535 + 0.2073071593
= 0.2836 + 0.3834 + 0.2073
= 0.8743

Question 20.
Consider five mice from the same litter, all suffering from Vitamin A deficiency. They are fed a certain dose of carrots. The positive reaction means recovery from the disease. Assume that the probability of recovery is 0.73. What is the probability that atleast 3 of the 5 mice recover.
Solution:
Success = 2 × fails
p = 2q ⇒ p = 2(1 – p)
p = 2 – 2p ⇒ p + 2p = 2
3p = 2 and p = 2/3
q = 1 – p = 1 – 2/3
q = 1/3 and n = 5
The binomial destribution is
p (X = x) = nC_xp^xq^n-x
= 5C(2/3)^x (1/3)
(i) p(three successes) = p(x = 3)

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 10 Neural Control and Coordination Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter 10 Neural Control and Coordination

11th Bio Zoology Guide Neural Control and Coordination Text Book Back Questions and Answers

Part -I.

I. Choose The Best Options

Question 1.
Which structure in the ear converts pressure waves to action potentials?
a) Tympanic membrane
b) Organ of Corti
c) Oval window
d) Semicircular canal
Answer:
b) Organ of Corti

Question 2.
Which of the following pairings is correct
a) Sensory nerve – afferent
b) Motor nerve – afferent
c) Sensory nerve – ventral
d) Motor nerve – dorsal
Answer:
a) Sensory nerve – afferent

Question 3.
During synaptic transmission of nerve impulse, neurotransmitter (P) is released from synaptic vesicles by the action of ions
(Q). Choose the correct P and Q.
a) P = Acetylcholine, Q = Ca⁺⁺
b) P = Acetylcholine, Q = Na⁺
c) P = GABA, Q = Na⁺
d) P = Cholinesterase, Q = Ca⁺⁺
Answer:
a) P = Acetylcholine, Q = Ca⁺⁺

Question 4.
Examine the diagram of the two cell types A and B given below and select the correct option.
a) Cell – A is the rod cell found evenly all over retina
b) Cell – A is the cone cell more concentrated in the fovea centralis
c) Cell – B is concerned with colour vision in bright light
d) Cell – A is sensitive to bright light intensities

Answer:
c) Cell – B is concerned with colour vision in bright light

Question 5.
Assertion- The imbalance in concentration of Na⁺, K⁺ and proteins generates action potential.
Reason: To maintain the unequal distribution of Na⁺ and K⁺ , the neurons use electrical energy.
a) Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.
b) Both Assertion and Reason are true but the Reason is not the correct explanations of Assertion.
c) Assertion is true, but Reason is false.
d) Both Assertion and Reason are false.
Answer:
a) Both Assertion and Reason are true and Reason is the correct explanation of the Assertion.

Question 6.
Which part of the human brain is concerned with the regulation of body temperature?
a) Cerebellum
b) Cerebrum
c) Medulla oblongata
d) Hypothalamus
Answer:
d) Hypothalamus

Question 7.
The respiratory centre is present in the
a) Medulla oblongata
b) Hypothalamus
c) Cerebellum
d) Thalamus
Answer:
a) Medulla oblongata

Question 8.
Match the following human spinal nerves in column I with their respective number in column II and choose the correct option
Column I Column 11
(P) Cervical nerves
(Q) Thoracic nerve
(R) Lumbar nerve
(S) Coccygeal nerve
(i) 5 pairs
(ii) 1 pair
(iii) 12 pairs
(iv) 8 pairs
a) (P-iv), (Q-iii), (R-i), (S-ii)
b) (P-iii), (Q-i), (R-ii), (S-iv)
c) (P-iv), (Q-i), (R-ii), (S-iii)
d) (P-ii), (Q-iv), (R-i), (S-iii)
Answer:
a) (P-iv), (Q-iii), (R-i), (S-ii)

Question 9.
Which of the following cranial nerve controls the movement of eye ball?
a) Trochlear nerve
b) Optic nerve
c) Olfactory nerve
d) Vagus nerve
Answer:
a) Trochlear nerve

Question 10.
The abundant intracellular cation is
a) H⁺
b) K⁺
c) Na⁺
d) Ca⁺⁺
Answer:
b) K⁺

Question 11.
Which of the following statements is wrong regarding conduction of nerve impulse.
a) In a resting neuron, the axonal membrane is more permeable to K⁺ ions and nearly impermeable to Na⁺ ions.
b) Fluid outside the axon has a high concentration of Na⁺ ions and low concentration of K⁺, in a resting neuron.
c) Ionic gradient s are maintained by Na⁺ K⁺ pumps across the resting membrane, which transport 3 Na ions outwards for 2K⁺ into the cell.
d) A neuron is polarized only when the outer surface of the axonal membrane possess a negative charge and its inner surface is positively charged.
Answer:
b) Fluid outside the axon has a high concentration of Na⁺ ions and low concentration of K⁺, in a resting neuron.

Question 12.
All of the following are associated with the myeline sheath except
a) Faster conduction of nerve impulses
b) Nodes of Ranvier forming gaps along the axon
c) Increased energy output for nerve impulse conduction
d) Saltatory conduction of action potential
Answer:
c) Increased energy output for nerve impulse conduction

Question 13.
Several statements are given here in reference to cone cells which of the following option indicates all correct statements for cone cells? Statements
(i) Cone cells are less sensitive in bright light than Rod cells
(ii) They are responsible for colour vision
(iii) Erythropsin is a photo pigment which is sensitive to red colour light
(iv) They are present in fovea of retina
a) (iii), (ii) and (i)
b) (ii), (iii) and (iv)
c) (i), (iii) and (iv)
d) (i), (ii) and (iv)
Answer:
c) (i), (iii) and (iv)

Question 14.
Which of the following statement concerning the somatic division of the peripheral neural system is incorrect?
a) Its pathways innervate skeletal muscles
b) Its pathways are usually voluntary
c) Some of its pathways are referred to as reflex arcs
d) Its pathways always involve four neurons
Answer:
d) Its pathways always involve four neurons

Question 15.
When the potential across the axon membrane is more negative than the normal resting potential, the neuron is said to be in a state of
a) Depolarization
b)FIyperpo1ariation
c) Repolarization
d) Hypopolaiization
Answer:
c) Repolarization

Question 16.
Why is the blind spot called so?
Answer:
Slightly below the posterior pole of the eye, the optic nerve and the retinal blood vessels enter the eye. This region is devoid of rods and cones. Hence, this region is called blind spot.

Question 17.
Sam’s optometrist tells him that his intraocular pressure is high. What is this condition called and which fluid does it involve?
Answer:

• The increase in intraocular pressure leads to the disease called Glaucoma.
• Any block in the canal of Schlemm increases the intraocular pressure of aqueous humor and leads to ‘Glaucoma’ where the optic nerve and the retina are compressed due to pressure.

Question 18.
The action potential occurs in response to a threshold stimulus: but not at sub-threshold stimuli. what is the name of the principle involved?
Answer:
When we cry, the tears come out of the tear glands under the eyelids and drain through the tear duct that empties into the nose. It mixes with mucus there and the nose runs.

Question 19.
Pleasant smell of food urged Ravi to rush into the Kitchen. Name the parts of the brain involved in the identification of food and emotional responses to odour
Answer:
The hypothalamus contains a pair of small rounded body called mamillary bodies that are involved in olfactory reflexes and emotional responses to odour
This is also act as centre for appetite thirst and heat regulation.

Question 20.
Cornea transplant in humans is almost never rejected State the reason.
Answer:
The cornea does not have blood vessels. Hence there is no possibility of rejection when the cornea is transplanted from one person to another person.

Question 21.
At the end of repolarisation, the nerve membrane gets hyperpolarized Why?
Answer:
If repolarization becomes more negative than the resting potential – 70mV to about – 90mV it is called hyperpolarization.

Question 22.
Label the parts of the neuron.
Answer:

A- Nucleus with nucleolus
B- Axolemma
C- Dendrites
D- Myelin sheath, Nucleus
E- Axon (Direction of signal transmission)
F- Node of Ranvier.

Question 23.
The choroid plexus secretes cerebral spinal fluid List the function it.
Answer:
Cerebrospinal fluid provides buoyancy to the central nervous system.

1. It acts as a shock absorber for the brain and spinal cord.
2. It nourishes the brain cells by transporting food and oxygen.
3. It carries harmful metabolic wastes from the brain to the blood.
4. It maintains constant pressure inside the cranial vessels.

Question 24.
What is the ANS controlling center? Name the parts that are supplied by the ANS?
Answer:
Controlling center – autonomic neural system. Controlling organs.

1. Eyes
2. Salivary Glands
3. Heart
4. Lungs
5. Stomach
6. Liver
7. Kidney
8. Intestines
9. Bladder

Question 25.
Why the limbic system is called the emotional brain. Name the parts of it?
Answer:
The limbic system is a set of components located on both sides of the thalamus present in the inner part of the cerebral hemisphere. It includes the olfactory bulbs, cingulate gyrus, mammillary body, amygdala, hippocampus and hypothalamus. The limbic system plays a primary role in the regulation of pleasure, pain, anger, fear, sexual feeling, affection and memory. Hence it is called the emotional brain.

Question 26.
Classify receptors based on the type of stimuli.
Answer:

Question 27.
Name the first five cranial nerves, their nature and their functions
Answer:

Question 28.
The sense of taste is considered to be the most pleasurable of all senses. Describe the structure of the receptor involved with a diagram.
Answer:

• The sense of taste is considered to be the most pleasurable of all senses.
• The tongue is provided with many small projections called papillae.
• Taste buds are located mainly on the papillae.
• Taste buds are flask-shaped.

There are two major types.

• Gustatory epithelial cells or taste cells.
• Basal epithelial cells or repairing cells.

• Long microvilli called gustatory hairs project from the tip of the gustatory cells and extend through a taste pore to the surface of the epithelium.
• Gustatory hairs are the sensitive portion of the gustatory cells and they have sensory dendrites which send the signal to the brain.
• The basal cells that act as stem cells divide and differentiate into new gustatory cells.

Question 29.
Describe the structures of olfactory receptors?
Answer:
The smell receptors are excited by air-borne chemicals that dissolve in fluids. The yellow coloured patches of olfactory epithelium form the olfactory organs that are located on the roof of the nasal cavity.

The olfactory epithelium is covered by a thin coat of mucus layer below and olfactory glands bounded connective tissues, above. It contains three types of cells: supporting cells, Basal cells and millions of pin-shaped olfactory receptor cells (which are unusual bipolar cells).

The olfactory glands and the supporting cells secrete the mucus. The unmyelinated axons of the olfactory receptor cells are gathered to form the filaments of olfactory nerve [cranial nerve-I] which synapse with cells of olfactory bulb.

The impulse, through the olfactory nerves, is transmitted to the frontal lobe of the brain for identification of smell and the limbic system for the emotional responses to odour.

Part-II.

11th Bio Zoology Guide Neural Control and Coordination Additional Important Questions and Answers

I. Choose The Correct Answer

Question 1.
What is the functional unit of the nervous system?
a) Neuroglial cells
b) Neuron
c) Nephron
d) Axon
Answer:
b) Neuron

Question 2.
Name the nutritive cells of neuron.
a) Axon
b) Neuroglia
c) Schwann’s cell
d) Epithelial cells.
Answer:
b) Neuroglia

Question 3.
Name the cell organelle which is not seen in the nerve cell.
a) Mitochondria
b) Golgi apparatus
c) Centrioles
d) Nucleus
Answer:
c) Centrioles

Question 4.
Name the plasma membrane which surrounds the neurons?
a) Neurilemma
b) Axolemma
c) Myalin membrane
d) Sarcolemma
Answer:
a) Neurilemma

Question 5.
Name the plasma membrane surrounds the axon?
a) Neurilemma
b) Myalin membrane
c) Sarcolemma
d) Axolemma
Answer:
d) Axolemma

Question 6.
Where is Nissl’s bodies seen in the nerve cell?
a) Cell body and dendrites
b) Cell body and axon
c) Cell body and myalin sheath
d) Cell body and end plate of axon.
Answer:
a) Cell body and dendrites

Question 7.
Name the cell organell which is not seen in the axons.
a) Mitochondria
b) Golgi apparatus
c) Centriole
d) Endoplasmic reticulum
Answer:
b) Golgi apparatus

Question 8.
Cell forms the myalin sheath ……………..
a) Schwaan’s cell
b) Neuroglial cells
c) Nephron
d) Epithelial cells
Answer:
a) Schwaan’s cell

Question 9.
Which part of the nerve cells do not contain myalin sheath.
a) Axon
b) Cell body
c) Dentrites
d) Axon end plate
Answer:
c) Dentrites

Question 10.
Which of the following does the work of phagocytosis of microbes during the infection of the brain
a) Schwann cells
b) Node of Ranvier
c) Neuroglial cells
d) Neurilemma
Answer:
c) Neuroglial cells

Question 11.
Find out the correct statement
a) The short nerve fibres are called as dentrites.
b) The membrane surrounds the neuron is axolemma.
c) The longest sciatic nerve runs from the base of the spine to the big toe of each foot
d) Schwann cell’s do not synthesize myalin sheath
Answer:
c) The longest sciatic nerve runs from the base of the spine to the big toe of each foot

Question 12.
Find out the wrong pair
a) Multi polar neuron: One axon and two or more dentrites.
b) Bi polar neurons: One axon and more than two dentrites.
c) Uni polar neurons: Short process axon.
d) Synaptic Knob: Neurotransmitters
Answer:
b) Bi polar neurons: One axon and more than two dentrites.

Question 13.
This substance is more in the tissue fluid of cytoplasm of axolemma?
a) Sodium chloride and bicarbonates.
b) Nutritious substances and oxygen.
c) Potassium and magnesium phosphate.
d) All the above.
Answer:
c) Potassium and magnesium phosphate.

Question 14.
Match the following and find the answer.

Answer:
c) i- B,ii – D,iii – C,iv – A

Question 15.
Name the gaps in the myelin sheath between adjacent Schwann.
a) Nodes of Ranvier
b) Nodes of axon
c) Nodes of cyton
d) Nodes of dentrites
Answer:
a) Nodes of Ranvier

Question 16.
Where are bipolar neurons situated?
a) Cranial nerves
b) Olfactory lobes of brain
c) Spinal nerves
d) Skin
Answer:
b) Olfactory lobes of brain

Question 17.
Where are Bipolar neurons situated?
a) Spinal cord
b) Retina
c) Inner ear
d) Brain.
Answer:
a) Spinal cord

Question 18.
Find out the odd one.
a) Schwann cell – Myalin sheath
b) Synaptic knob – Synaptic vesicles
c) Bipolar neuron – Cranial nerves
d) Multipolar neuron – Spinal nerves.
Answer:
c) Bipolar neuron – Cranial nerves

Question 19.
Where is Bipolar neurons meet?
a) Synapses
b) Synaptic cleft
c) Synaptic vesicle
d) Synaptic Knob
Answer:
a) Synapses

Question 20.
Match and find the correct sequence.

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

Question 21.
Central nervous system forms from this layer during embryonic development.
a) Endoderm
b) Ectoderm
c) Mesoderm
d) Middle layer.
Answer:
b) Ectoderm

Question 22.
Find out whether the following statements are true or false. Find out the correct sequence.
i. The thick outer covering of the brain is dura matter
ii. The space between pia matter and dura matter is subarachnoid space.
iii. The membrane that surrounds the brain is piamalter
iv. The space between arachnoid and pia mater is subarachnoid space
a) I – False; II – False; III – True; IV – True
b) I-True; II-False; III-True; IV-True
c) I – True; II – False; III – False; IV – True
d) I-True; II-False; III-True; IV-False
Answer:
b) I-True; II-False; III-True; IV-True

Question 23.
Which is considered as the seat of intelligence.
a) Cerebellum
b) Cerebrum
c) Medulla oblongata
d) Pons.
Answer:
b) Cerebrum

Question 24.
Find out whether the following statements are true or false.
a) At resting membrane potential the efflux of potassium is more than the influx of sodium from the outer surface of the neurilemma.
b) When the stimulus is sent from the cell body to the axon there is no creation of action potential.
c) The spike potential is +45mV.
d) The threshold potential is +55mV.
i) a) True b) True c) False d) False
ii) a) False b) True c) True d) True
iii) a) True b) False c) True d) True
iv) a) True b) False c) True d) False
Answer:
iv) a) True b) False c) True d) False

Question 25.
Find out the wrong pair
a) Synapses – The junction of two neurons
b) Neurotransmitter – Postsynaptic neuron
c) Synaptic vesicles – A small bag filled with chemicals
d) Piamatter – Membrane which closely adheres to the brain.
Answer:
b) Neurotransmitter – Postsynaptic neuron

Question 26.
………………. is the part of the fore-brain.
a) Cerebrum – Mesencephalon
b) Cerebrum – Prosencephalon
c) Cerebrum – Diencephalon
d) Cerebrum – Parietal lobe.
Answer:
c) Cerebrum – Diencephalon

Question 27.
…………………….. is useful in diagnosis of neurological and sleep disorders.
a) PET
b) CT
c) X – rays
d) EEG
Answer:
d) EEG

Question 28.
Name the structure which connects cerebral hemisphere
a) Choroid tissue
b) Corpus callosum
c) Neuroglia tissue
d) Pineal body
Answer:
b) Corpus callosum

Question 29.
Match and find out the correct sequence.

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

Question 30.
Assertion: Statement A- The cortex of cerebrum consists of grey matter.
Statement B- The reason for the grey matter is due to the presence of non – myelinated sheath.
a) Statement A- True, Statement B – False
b) Statement A and B are true
c) Statement A- False the statement B- True.
d) Statement A and B are false.
Answer:
b) Statement A and B are true

Question 31.
Match and find the correct answer.
1. Broca area a. Perception of taste.
2. The pre-central gyrus b. Voluntary movements
3. The postcentral gyrus c. Aggression
4. Amygdala d. Speech function
a) I-a II-b III-c IV-d
b) I-d II-b III-c IV-a
c) I-d II-b Ill-a IV-c
d) I-a II-b III-c IV-d
Answer:
c) I-d II-b III-a IV-c

Question 32.
Assertion: Statement S – Brain controls emotions and feelings.
Statement T – There are no sensory neurons in the brain. Hence it cannot sense the pain.
a) Statement – S – True. Statement T – False
b) Statement – S – True Statement T – True
c) Statement – S – False Statement T – False
d) Statement S – False Statement T – True
Answer:
b) Statement – S – True Statement T – True

Question 33.
Which is considered as the relay centre for impulses
a) Medulla oblongata
b) Cerebrum
c) Hypothalamus
d) Thalamus
Answer:
d) Thalamus

Question 34.
Which indicates A, B, C and D in the following diagram

(a)
a) Temporal lobe
b) Frontal lobe
c) Parietal lobe
d) Cerebellum
(b)
a) Cerebellum
b) Parietal lobe
c) Temporal lobe
d) Frontal lobe
(c)
a) Cerebellum
b) Frontal lobe
c) Temporal lobe
d) Parietal lobe
(d)
a) Parietal lobe
b) Cerebellum
c) Frontal lobe
d) Temporal lobe
Answer:
(b)
a) Cerebellum
b) Parietal lobe
c) Temporal lobe
d) Frontal lobe

Question 35.
Find out the wrong statement.
a) The pre-central gyrus is called a motor strip.
b) The post-central gyrus is called a sensory strip.
c) The medulla oblongata controls respiration.
d) Wernicke area of the brain involved in the comprehension of speech.
Answer:
d) Wernicke area of the brain involved in the comprehension of speech.

Question 36.
The melatonin hormone which controls the sleep-wake cycle is secreted by
a) Pineal body
b) Thalamus
c) Hypothalamus
d) Medulla oblongata
Answer:
a) Pineal body

Question 37.
The lower portion of the midbrain consists of a pair of longitudinal nervous bands called
a) Emotional brain
b) Cerebral peduncles
c) Pons
d) Vermis
Answer:
b) Cerebral peduncles

Question 38.
The cauda equina presents in
a) Cerebrum
b) Thalamus
c) Hippo cambus
d) Spinal cord
Answer:
d) Spinal cord

Question 39.
Match and find the correct answer.
i) Thalamus – A) Respiration Gastric Pits.
ii) Hypothalamus – B) Vision Hearing
iii) Mid brain – C) Satiety centre
iv) Medulla oblongata – D) Learning memory

Answer:
a) i- D,ii – C,iii – B,iv – A

Question 40.
The cluster of nerve tissue in the cell body of neurons are called as
a) Gyri
b) Sulci
c) Vermis
d) Nerve ganglion.
Answer:
d) Nerve ganglion.

Question 41.
Find out the wrong pair
a) Cervical nerve – 8 pairs
b) Thoracic nerve – 12 pairs
c) Sacrum nerve – 4 pairs
d) Coccyx nerve – 1 pair
Answer:
c) Sacrum nerve – 4 pairs

Question 42.
What is the amount of cerebrospinal fluid secreted in an adult?
a) 500 ml
b) 150 ml
c) 400 ml
d) 250 ml
Answer:
b) 150 ml

Question 43.
The dissolved nicotene and alcohol in …………………… and ………………… minutes reach the brain.
a) 7 and 8 minutes
b) 6 and 7 minutes
c) 7 seconds and 6 minutes
d) 7 and 5 minutes.
Answer:
c) 7 seconds and 6 minutes

Question 44.
Name the structure that regulates homeostasis.
a) Mammillary body
b) Pineal body
c) Hypothalamus
d) Pituitary.
Answer:
a) Mammillary body

Question 45.
What is brain stem.
a) The structure seen in between spinal cord and cerebellum.
b) The region between Diencephalon and spinal cord
c) The region between medulla oblongata and cerebrum.
d) The region between medulla oblongata and mid-brain.
Answer:
b) The region between Diencephalon and spinal cord

Question 46.
What is the function of corpora quadri gemina?
a) Vision and hearing
b) Vision and homeostasis
c) Hearing and sense of touch
d) Hearing and vomiting.
Answer:
a) Vision and hearing

Question 47.
The region seen in the mid of cerebellum.
a) Corpus callosum
b) Pineal body
c) Pituitary
d) Vermis.
Answer:
d) Vermis.

Question 48.
What is the function of the interneuron?
a) Impulses from afferent and efferent neurons.
b) Impulses transmitted from efferent neurons to afferent neurons.
c) Impulses transmitted from central nervous system to receptor organs
d) From nerve transmitters to the spinal cord
Answer:
a) Impulses from afferent and efferent neurons.

Question 49.
Which part of the brain controls the unconditioned reflux?
a) The cortex of cerebrum
b) The medulla of brain
c) Cerebellum
d) pons.
Answer:
a) The cortex of cerebrum

Question 50.
……………………..pair of nerves from cranium and
…………………….. pair of nerves from spinal cord
a) 10 and 31
b) 12 and 31
c) 31 and 12
d) 31 and 10.
Answer:
b) 12 and 31

Question 51.
How much cerebrospinal fluid is synthesized in adults?
a) 200ml
b) 300ml
c) 150ml
d) 100ml.
Answer:
c) 150ml

Question 52.
What is the function of vagus nerve?
a) It regulates the function of abdominal structure
b) It regulates the speech and swallowing
c) It regulates the homeostasis of the body
d) Taste perception
Answer:
a) It regulates the function of abdominal structure

Question 53.
Name the neural system which is auto functioning and self-governed.
a) Somatic neural system
b) Automatic neural system
c) Peripheral neural system
d) Limbic system.
Answer:
b) Automatic neural system

Question 54.
Name the structure that regulates the autonomic neural system.
a) Cerebrum
b) Cerebellum
c) Hypothalamus
d) Pons.
Answer:
c) Hypothalamus

Question 55.
Name the lubricating fluid which is secreted from the gland present at the base of the eyelashes.
a) Lacrymal gland
b) Cerebro-spinal fluid
c) Thymus gland
d) Sebaceous glands.
Answer:
d) Sebaceous glands.

Question 56.
Find the ABC and D in the diagram

a) a) Tear duct b) Sciera c) Iris d) Tear gland
b) a) Sciera b) Iris c) Tear gland d)Tear duct
c) a) Tear duct b) Iris c) Sclerad d)lTear duct
d) a) Tear gland b) Sclera c) Tear duct d) Iris.
Answer:
d) a) Tear gland b) Sclera c) Tear duct d) Iris.

Question 57.
Name the tissue which forms the non-vascular transparent coat cornea
a) Stratified squamous epithelium
b) Squamous epithelium
c) Canal of schlemm
d) All the above.
Answer:
a) Stratified squamous epithelium

Question 58.
Assertion: In bright light the circular muscle in the iris contract so that the size of the pupil decreases and the light enter is regulated Reason: In dim light, the radial muscle contract the pupil size increases and less light enters the eye.
a) The assertion true: but reason wrong
b) The assertion and reason are true
c) The assertion is true but reason does not explain the assertion
d) The assertion and reason are wrong.
Answer:
a) The assertion true: but reason wrong

Question 59.
Name the yellow flat spot at the centre of the posterior region of the retina.
a) Blind spot
b) Scelera
c) Iris
d) Maculalutea
Answer:
d) Maculalutea

Question 60.
Which colour is perceived through chloropsin is sensitive to the medium wavelength of 530 mm
a) Red cones
b) Green cones
c) Blue cones
d) Red cells.
Answer:
b) Green cones

Question 61.
Name the glands that secrete tear.
a) Lacrymal gland
b) Sebaceous gland
c) Mandibular gland
d) Choroid plexues
Answer:
a) Lacrymal gland

Question 62.
…………………… enzyme is present in the tear.
a) Ptyalin
b) Lysozyme
c) Lipase
d) Erypsin.
Answer:
b) Lysozyme

Question 63.
Name the structure where more cones present.
a) Foveacenlralis
b) Maculalutea
c) Retina
d) Blind spot.
Answer:
a) Foveacenlralis

Question 64.
……………………………….. people can see the nearby object but cannot see the distant object.
a) Astigmatism
b) Presbiopia
c) Hypermetropia
d) Myopia
Answer:
d) Myopia

Question 65.
The concave lens helps in correct ………………. defect
a) Myopia
b) Hyper metropia
c) Astigmatism
d) Presbiopia
Answer:
a) Myopia

Question 66.
Which of the defect is depicted in the following diagram:

a) Emmetropia
b) Myopia
c) Hypermetropia
d) Astigmatism.
Answer:
b) Myopia

Question 67.
Match and find the correct sequence.

a) 1 -a 2-b 3-c 4-c
b) 1 -d 2-b 3-a 4-c
c) 1-d 2-a 3-a 4-b
d) 1-d 2-c 3-b 4-c
Answer:
b) 1 -d 2-b 3-a 4-c

Question 68.
Name the organ which regulates vision perception and homeostasis.
a) Ear
b) Eye
c) Cerebrum
d) Cerebellum.
Answer:
a) Ear

Question 69.
Find out the wrong pair.
a) Pinna – Eardrum
b) Oval window – Round window
c) Cochlea – Malleus
d) Perilymph – Endolymph
Answer:
c) Cochlea – Malleus

Question 70.
Indicate ABC and D in the Diagram.

a)
a) lncus
b) Eardrum
c) Organ of Corti
d) Tactoreal membrane.
b)
a) Organ of cortri
b) Incus
c) Tectoreal membrane
d)Eardrum
c)
a) Eardrum
b) Incus
c) Organ of Corti
d) Tectoreal membrane
d)
a) Eardrum
b) Incus
c) Tectoreal membrane
d) Organ of Corti
Answer:
d)
a) Eardrum
b) Incus
c) Tectoreal membrane
d) Organ of Corti

Question 71.
Find out the wrong statement.
a) The equilibrium receptor regions called maculae are involved in detecting the linear movement of the head.
b) The otoliths are made up of calcium
c) The crista ampullaris is to detect rotational movement of the head
d) Severe hearing loss occurs with frequent exposure to sound with intensities greater than50db.
(The 90db will affect the hearing).
Answer:
d) Severe hearing loss occurs with frequent exposure to sound with intensities greater than50db.

Question 72.
A person on his way to a village in a car for weekend holidays after finishing the office work. As he is very tired he begins to feel drowsy. He turns up the car stereo volume opens the car window and has sips ice-cold water.
How do these actions keep him awake? The increase in the number of sensory stimuli he received is relayed to the cerebral cortex which gets activated and prevents sleeping,
a) Spinal cord
b) Cerebrum
c) Medulla oblongata
d) Cerebellum.
Answer:
c) Medulla oblongata

Question 73.
Name the structure that connects the middle ear and pharynx.
a) Eustachian tube
b) Middle ear
c) Oval window
d) Organ of the cortii.
Answer:
a) Eustachian tube

Question 74.
Which part of the ear have bony labyrinth and membranous labyrinth?
a) External ear
b) Inner ear
c) Middle ear
d) None of the above.
Answer:
b) Inner ear

Question 75.
Name the structure present in the bony labyrinth.
a) Cochlea, vestibule, maleus
b) Cochlea, vestibule Incus
c) Cochlea semicircular canals, stapes
d) Cochlea, vestibule semicircular canals.
Answer:
d) Cochlea, vestibule semicircular canals.

Question 76.
Where is the stereo cilia cells present in the ear?
a) Scala media
b) Scala vestibuli
c) Scala tymnani
d) Middle ear.
Answer:
a) Scala media

Question 77.
Match and find the correct sequence.

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

Question 78.
When a cockroach tries to enter into the ear of a sleeping person, which one of the following process will start?
a) Unconditioned reflex
b) Neuro muscular fatigue
c) Stimulation of negative feedback mechanism
d) conditioned reflex
Answer:
a) Unconditioned reflex

Question 79.
What is the number of nerve cells present in the brain
a) 90 million
b) 100 billion
c) 90 billion
d) 100 million
Answer:
b) 100 billion

(2 Marks)

II. Write Very Short Answer

Question 1.
What are the two branches of human nervous system?
Answer:

1. Central nervous system
2. Peripheral nervous system

Question 2.
What is meant by Neuroglia? What are its functions?
Answer:
The non-nervous special cells called neuroglia from the supporting cells of the nervous tissue.

1. Providing nourishment to the neurons
2. Repairing the injured tissues
3. It helps in dividing and regeneration
4. Acting as phagocyte cells to engulf the foreign particles at the time of any injury to the brain.

Question 3.
Differentiate the functions of myelinated and non-myelinated neurons.
Answer:

Question 4.
Give notes on (a) Synaptic Knob (b) Neurotransmitters (c) Inter neural space.
Answer:

• Synaptic Knob: Distant end of the axon terminates into a bulb
• Synaptic vesicles: Vesicles filled with neurotransmitters
• Inter neural space – The space between presynaptic and postsynaptic neurons.

Question 5.
What is meant by nerve impulses?
Answer:
A nerve impulse is a series of electrical impulses which travel along with the nerve fibre.

Question 6.
What is meant by resting potential?
Answer:
The electrical potential difference across the plasma membrane of a resting neuron is called the resting potential.

Question 7.
What is meant by threshold potential?
Answer:
During depolarization when enough Na⁺ ions enter the cell the action potential reaches a certain level called threshold potential. (-55 mV)

Question 8.
What is threshold stimulus?
Answer:
The particular stimulus which is able to bring the membrane potential to the threshold is called the threshold stimulus.

Question 9.
What is meant by all or none principle?
Answer:
The action potential occurs in response to a threshold stimulus but does not occur at sub-threshold stimuli. This is called the all or none principle.

Question 10.
What is the cause of brain tumours?
Answer:

• Glial cells: Nerve cells do not divide but glial cells do not lose the ability to undergo cell division.
• So most brain tumours of neural origin consist of glial cells.

Question 11.
What are meninges?
Answer:
The brain is covered by outer Duramater, the median Arachnoid mater and the inner Piamater. These membranes are called meninges.

Question 12.
What is meant by lazy gate?
Answer:
During hyper polarization the K⁺ion gates are more permeable to K⁺ even after reaching threshold level it closes slowly hence called lazy gates.

Question 13.
What is spike potential?
Answer:
Due to the rapid influx of Na⁺ ions the membrane potential shoots rapidly up +45 mV which is called the spike potential.

Question 14.
What is meant by repolarisation?
Answer:
When the membrane reaches the spike potential the potassium ions K⁺ efflux from the axolemma and hence form negative potential. This is called repolarisation.

Question 15.
What is Hyper polarisation?
Answer:
If repolarisation becomes more negative than the resting potential -70 mV to about -90 mV it is called hyper polarisation.

Question 16.
Which decides the speed of the conduction of a nerve impulse?
Answer:

• The conduction speed of a nerve impulse depends on the diameter of axon.
• The greater the axon’s diameter the faster is the conduction.

Question 17.
What is septum pellucidum?
Answer:
A thin membrane which separates the lateral ventricles I and II is called the septum pellucid

Question 18.
What is the difference between sub durai space and sub arachnoid space
Answer:

Question 19.
What is meant by sulcus and gyrus? What is its functions.
Answer:

• Gyri – The convolution seen in the cerebrum.
• Sulci – The shallow grooves increase the surface area of the cerebral cortex.

Question 20.
Name the lobes of cerebrum?
Answer:

1. Pair of frontal
2. Pair of parietal
3. Pair of temporal
4. Occipital

Question 21.
What is the function of proca?
Answer:
It involves in speech function.

Question 22.
What is meant by a blood brain barrier.
Answer:
It protects the brain by preventing many foreign substances in our vascular system from reaching the brain.

Question 23.
Which part of the cerebrum is called as sheet of emotions?
Answer:
The cortex of parietal occipital and temporal.

Question 24.
What is meant by motor area?
Answer:

• The area which controls the voluntary muscular movements lies in the posterior part of the frontal lobes.
• Functions They receive and interpret the sensory impulses.

Question 25.
What is the function of association area?
Answer:
They deal with memory communications learning and reasoning.

Question 26.
Where is pineal body situated? What is its functions?
Answer:

It is situated behind the choroid plexus the epithalamus forms short stalk
Functions
The melotoxin secreted by the pineal body regulates sleep wake cycle.

Question 27.
For a man to live all parts of the brain is important. How is brain divided into?
Answer:

• Cerebrum
• Thalamus
• Hypothalamus
• Pons
• Cerebellum
• Medulla oblongata

Question 28.
What is meant by corpus callosum?
Answer:
The two hemispheres of cerebrum is connected with the nerve band known as corpus callosum.

Question 29.
What is meant by brain stem? What are its parts?
Answer:
The region between spinal cord and diencephalon.

1. Mid-brain
2. Pons varoli
3. Medulla oblongata

Question 30.
What is meant by corpora quadri gemina? What are its functions.
Answer:

• The four papillae seen on the dorsal side of mid brain.
• Perception of vision and hearing

Question 31.
What is meant by reflex arc?
Answer:

• It is a fast involuntary unplanned sequence of actions that occurs in response to a particular stimulus.
• The nervous elements that involved in carrying out reflex action constitute reflex arc.

Question 32.
What are the functions of cerebellum?
Answer:
The cerebellum controls and co-ordinates muscular movements and body equilibrium.

Question 33.
What is meant by receptors?
Answer:
The organ which made us aware of changes occur in our surrounding is called receptors.

Question 34.
What is meant by voluntary neural system?
Answer:
It is the part of the peripheral neural system associated with the voluntary control of body movements via skeletal muscles

Question 35.
Name the bacteriocidal substance present in the tears? Where is it seen? Name its secretion?
Answer:

• Lysosome enzyme
• Seen in tears.
• Lacrymal glands. 1ml is secreted in a day.

Question 36.
What are mammillary bodies? What are its functions?
Answer:

• The hypothalamus contains a pair of small rounded body called mammillary bodies.
• Functions: It is involved in olfactory reflexes and emotional responses to odour.

Question 37.
What are cerebral peduncles?
Answer:
The region between diencephalon and the pons is called midbrain. It consists of a pair of longitudinal bands of nervous tissue called cerebral peduncles.

Question 38.
What is brain stem? What are its parts?
Answer:
It is the part of the brain between the spinal cord and the diencephalon.
Organs: Mid-brain, Pons, Medulla oblongata

Question 39.
What is caudo equina?
Answer:

• After the 2nd lumbar vertebra the spinal nerves are greatly elongated
• The thick bundle of elongated nerve roots appears as a horse’s tail called as cauda equina.

Question 40.
Where is enlargement region seen in the spinal cord?
Answer:

• Cervical enlargement
• Lumbar enlargement.

Question 41.
What is meant by reflex action?
Answer:

• When a very quick response is needed the spinal cord can effect motor initiation as the brain and brings about an effect.
• This rapid action by spinal cord is called reflex action.

Question 42.
What is meant by peripheral nervous system?
Answer:
All nervous tissue outside the CNS is the nervous system.

Question 43.
What is meant by mixed nerve?
Answer:
Each spinal nerve is a mixed nerve containing both afferent (sensory) and efferent (motor) fibers.

Question 44.
What is meant by pre ganglionic neuron?
Answer:
Its cell body is in the brain or spinal card. Its myelinated axon exits the CNS as part of cranial or spinal nerve and end in an autonomic ganglion.

Question 45.
What is autonomic ganglion?
Answer:
The axons of pre ganglionic neuron and cell bodies of post ganglionic neuron includes autonomic ganglion.

Question 46.
What is post ganglionic neuron?
Answer:
It conveys nerve impulses from autonomic ganglia to visceral effector organs.

Question 47.
What are the two branches of autonomous nervous system?
Answer:

1. Sympathetic neural system
2. Parasympathetic neural system.
3. varying distances is called accommodation.

Question 48.
Give short notes on Lacrymal glands?
Answer:

• The tear secreting glands are known as Lacrymal glands.
• 1ml of tear is secreted in a day.
• Tear salts, mucous and lysozyme enzyme to destroy bacteria.

Question 49.
What is conjunctiva?
Answer:
It is a thin protective mucous membrane found lining the outer surface of the eye ball.

Question 50.
Dilation and congestion of the blood vessels due to local irritation or infections. What is the disease? When will it occur?
Answer:

• Conjunctivitis or madras eye.
• Irritation or infection are the cause of blood shot eye.

Question 51.
What is sty?
Answer:
Infection of ciliary glands by bacteria causes a painful pus filled swelling called a sty.

Question 52.
What are the three types of cell present on the neural retina?
Answer:

• Photo receptor cell
• Cones
• Rods
• Bipolar and ganglion cells.

Question 53.
What is cataract?
Answer:
Due to the changes in nature of protein the lens become opaque called cataract.

Question 54.
What is aqueous humour and vitreous humour
Answer:

• Aqueous humour – The fluid filled in between the cornea and iris.
• Vitreous humour – Fluid filled in between lens and retina.

Question 55.
Give notes on lens fibres?
Answer:
Eye lens is transparent and biconvex made up of long columnar epithelial cells called lens fibre, these cells are formed of crystalline protein.

Question 56.
What are the three layers of eye ball?
Answer:

1. Sclera – Outer coat
2. Choroid – Pigmented middle layer
3. Retina – Inner most layer

Question 58.
What is meant by maculae lutea?
Answer:
The yellow flat spot at the centre of the posterior region of the retina is called macula lutea. It is responsible for sharp detailed vision.

Question 59.
What is fovea centralis?
Answer:
A small depression present in the centre of the yellow spot is called fovea centralis which contains only cones.

Question 60.
What is blind spot?
Answer:
The optic nerves and the retinal blood vessels enter the eye slightly below the posterior pole whichis devoid of photoreceptors is called blind spot.

Question 61.
Why there is no cornea rejection during cornea transplantation?
Answer:

• There is little or no possibility of cornea rejection.
• This is because cornea does not have blood vessels.

Question 62.
What are the three ear ossicles?
Answer:

1. Malleus – hammer bone
2. Incus – anvil bone
3. Stapes – stirrup bone

Question 63.
What are the three chambers of cochlea?
Answer:

1. Scala vestibule
2. Scala tympani
3. Scala media

Question 64.
What is tectorial membrane?
Answer:
A roof like structure over hanging the organ of corti through out its length with the stiff gel membrane called tectorial membrane.

Question 65.
Name the receptors which are excited by airborne chemicals that dissolve in fluids?
Answer:
The receptors for taste and smell are the chemo receptors

Question 66.
What is tactile merkel disc?
Answer:
It is the light touch receptor lying in the deeper layer of epidermis.

Question 67.
What are the structures present in the membranous labyrinth?
Answer:

• Cochlea
• Vestibule
• Semi circular canals

Question 68.
What are the three chambers of cochlea? Name the membrane which separates these chambers?
Answer:

1. Scala vestibuli
2. Scala tympanii
3. Scala media

Separating membranes
Reisner’s membrane. It separates scala vestibuli from scala media
Basilar membrane. It separates scala media from scala tympani.

Question 69.
What is meant by stereo cilia?
Answer:

• The organ of corti contains numerous hair cells on the basilar membrane.
• Protruding from the apical part of each hair cell is hair like structures called stereo cilia.

Question 70.
What is proprioception?
Answer:
The ability to provide information about position and movements of the body is proprioception.

Question 71.
What is meant by vestibular system?
Answer:
This is the organ of balance this system is composed of fluid filled sacs and tubules.

Question 72.
Give notes on utriculus and sacculus?
Answer:
The utricle and saccule contain equilibrium receptor regions called maculae that are involved in detecting the linear movement of the head.

Question 73.
What is otolith?
Answer:

• Maculae contains hair cells. These hair cells contain calcareous particles called otoliths.
• It increases the inertia.

Question 74.
What are ampullae?
Answer:
At one end of each semicircular canal at its lower end has a swollen area called ampulla Each ampulla has sensory hair cells and supporting cells called crista ampullaris. The function is to detect rotational movement of the head.

Question 75.
Give the name of balancing structures which perform the following action.
a) Linear movement of the head
b) Changes occurring in body position.
c) Rotational movement of the head
Answer:

• Maculae
• Vestibular system
• Crista ampularis

Question 76.
What is the unit of sound? Give notes on our ability of sound perception?
Answer:

• The intensity of sound is measured in decibels. (dB)
• 0-50 dB is the threshold of hearing for normal ear.
• Prolonged exposure to sound with intensities greater than 90dB causes hearing loss.

Question 77.
What are chemo receptors?
Answer:

• The receptors for taste and smell are the chemo receptors
• The smell receptors are excited by air borne chemicals that dissolve in fluids.

Question 78.
What are olfactory organs? Where are they situated?
Answer:

• The yellow coloured patches of olfactory epithelium form the olfactory organs.
• They are located on the roof of the nasal cavity.

Question 79.
What are papillae?
Answer:
The tongue is provided with many small projection called papillae which is responsible for taste.

Question 80.
Give notes on taste buds.
Answer:

• The taste bud cells are subjected to huge amounts of friction because of their location and are routinely burned by hot foods.
• These are the most dynamic cells in the body and replaced every seven to ten days.

(3 Marks)

III. Short Answers

Question 1.
What are the three main functions of nervous system.
Answer:

• Sensory functions: It receives sensory input from internal and external environment.
  Motor functions: It transmits motor commands from the brain to the skeletal and muscular system.
• Autonomic functions: Reflex actions.

Question 2.
How do we classify neurons on the basis of its functions.
Answer:

• Afferent neurons – That take sensory impulses to the central nervous system from the sensory organs.
• Efferent neurons – That carry motor impulses from CNS to the effector organ.
• Inter neurons – That lie entirely within the CNS between the afferent and efferent neurons.

Question 3.
What is meant by depolarisation?
Answer:

• The inside of the axolemma becomes positively charged and negatively charged outside.
  This reversal of electrical charge is called depolarisation.

Question 4.
How is nerve impulses transmitted?
Answer:

• Inner to the axolemma the cytoplasm contains the infra cellular fluid with large amounts of potassium and magnesium phosphate with negatively charged proteins and other organic molecules.
• Outside the axolemma contains large amounts of sodium chloride bicarbonates CO² andmetabolic wastes
• Due to the charged particles present in the inner and outside of the axolemma are responsible for the conduction of nervous impulses.

Question 5.
What is meant by repolarisation?
Answer:

• When the axolemma reaches the spike potential the sodium voltage – gate closes and potassium – voltage gate opens.
• It checks influx of Na⁺ ions and initiation the efflux of K ions which lowers the number of positive ions within the cell. Thus the potential falls back towards the resting potential.

• The reversal of membrane potential inside the axolemma to negative occurs clue to efflux of K⁺ ions. This is called repolarisation.

Question 6.
What is meant by hyper polarisation.
Answer:

• If repolarisation becomes more negative than the resting potential -70 mV to about -90 mV.
  • It is called hyper polarisation. During this K⁺ ion gate are more permeable to K⁺ even after reaching the threshold level as it closes slowly hence called lazy gates.

• The membrane potential return to its original resting state when K⁺ ion channel close completely.
• During hyper polarization the Na⁺ voltage gate remains closed.

Question 7.
Give an account of the conduction speed of a nerve impulse.
Answer:

• If the axon’s diameter is greater the conduction will be faster.
• The myelinated axon conducts the impulse faster than the non – myelinated axon.

Question 8.
What is meant by saltatory conduction?
Answer:
The myelinated axon conduction the impulse faster than the non – myelinated axon.
The voltage gated Na⁺ and K⁺ channels are concentrated at the nodes of Ranvier as a result the impulse jumps node to node. This is called saltatory conduction.

Question 9.
Give an account of the membranes (meninges) of brain?
Answer:
Brain is covered by three cranial meninges.

1. The outer thicker layer is duramater which lines the inner surface of the cranial cavity.
2. The inner most layer which is adhered to the brain is piameter.
3. The median thin layer is arachnoid mater by a narrow subdural space.
4. The piameter is separated from the arachnoid mater by the subarachnoid space.

Question 10.
List out the functions of brain lobes?
Answer:

Question 11.
Why is thalamus considered as a important relay centre for impulse?
Answer:

• It serves as a relay centre for impulses between the spinal and brain and cerebrum.
• Information is sorted and edited.
• It plays a key role in learning and memory.
• It is a co-ordinating centre for sensory and motor signaling.

Question 12.
Why there may be a death due to the affectation of medulla oblongata?
Answer:

• Medulla controls cardio-vascular reflexes respiration and gastric secretions.
• If medulla is getting affected the circulation and respiration is affected.
• That may cause a death of a person.

Question 13.
Give notes on mid brain?
Answer:

• The midbrain is located between the diencephalon and the pons.
• The lower portion of the mid-brain consists of a pair of longitudinal bands of nervous tissue called cerebral peduncles.
• This relay impulses back and forth between cerebrum cerebellum pons and medulla.
• The dorsal position of the mid Brain consist of four rounded bodies called corpora quadrigemina which acts as a reflex center for vision and hearing.

Question 14.
What are the features we develop when there is a functional deficiency of serotonin and nor epinephrine?
Answer:
Features:

• negative mood
• loss of interest
• an in ability to experience pleasure
• suicidal tendencies.

Drugs:
Anti depressant drug can treat all this features.

Question 15.
Give notes on cerebro spinal fluid?
Answer:

• 150ml of cerebro spinal fluid is secreted in an adult.
• 500ml of cerebro spinal fluid is secreted in a day.
• Every 8 hours this fluid is rejuvenated.
• Choroid plexux carries harmful metabolic wastes from the brain to the blood.

Question 16.
Based on their position how the receptors are classified?
Answer:
1. Exteroceptors – They are located at the surface of the body.
These senses the hearing vision touch taste and smell.

2. Introceptors: They are located in the visceral organs and blood vessels.
They are sensitive to internal stimuli.

3. Prerprioceptors:
They provide information about position and movements of the body.

Question 17.
Your friend is returning home after his visit to USA. All at home are waiting for his arrival.
How would you feel? State the division of ANS that predominates and mention few changes take place in your body?
Answer:

• The sympathetic and parasympathetic neural system are is mainly involved.
• On seeing his friend out of the happiness his autonomic nervous system is stimulated and he gets tears in his eyes.
• After sometime the parasympathetic stops the secretion of tears.

Question 18.
What is meant by depression? What are its symptoms?
Answer:

• Depression is a functional deficiency of serotonin and nor epinephrine.
• This disorder is characterized by a pervasive negative mood, loss of interest an inability to experience pleasure and suicidal tendencies.

Question 19.
When dust falls on our eyes like eyelids close immediately not waiting for our willingness, on touching a hot pan the hand is with drawn rapidly. Do you know how this happens?
Answer:
Reflex axon.
When a very quick response is needed the spinal cord can effect motor initiation as the brain and brings about an effect it is due to fast action of spinal cord.

Question 20.
What are the differences between conditioned and unconditioned reflex.
Answer:

Question 21.
What is the difference between exteroceptors and interoceptors.
Answer:

Question 22.
Where are lens fiber seen? What is the substance that fills it?
Answer:

• The lens is a transparent biconvex structure made up of slender columnar epithelial cells.
• These cells are called as lens fibre.
• These cells are formed of crystaline protein.

Question 23.
What is meant by accommodation of eye? List the structures that are involved in this process?
Answer:

• The ability of the eyes to focus objects at varying distances is called accommodation.
• This is achieved by suspensory ligament ciliary muscle and ciliary body

Question 24.
Name the structures that helps in fixing eyes in the eye ball?
Answer:
Eye is held in its position with the help of six extrinsic muscles.
They are
Superior
Interior
Lateral
Median rectus muscle
Superior oblique
Inferior oblique

Question 25.
Name the accessory structure which protects eye?
Answer:

• Eye lashes and the eye brows
• They help to protect the eyeballs from foreign objects, perspiration and from direct sunrays.
• Sebaceous glands or ciliary glands.
• They secrete a lubricating fluid.
• Lacrymal glands.
• Secrete tears.
• Tears contain salts mucus and lysozyme enzyme to destroy bacteria.

Question 26.
Give an account of aqueous humour?
Answer:

• It supplies nutrients and oxygen to the lens cornea and retinal cells.
• It is produced and drained at same rate.
• It maintains a constant infra ocular pressure of about 16 mmHg.

Question 27.
Give short notes on glaucoma.
Answer:
Any block in the canal of Schlemm increases the intra ocular pressure of aqueous humour and leads to “glaucoma when the optic nerve and the retina are compressed due to pressure.

Question 28.
Name the detects of detraction.
Answer:

• Myopia
• Hyper metropia
• Astigmatism
• Cataract

Question 29.
Give notes on pigments of colour vision
Answer:

• Redcones. It contains visual pigment erythropsin which is sensitive to long wavelength close to 560 nm.
• Green cones – It has a pigment chloropsin which is sensitive to medium wavelength of 530 nm.
• Blue cones – It has a pigment which is sensitive to short wavelength of 420 nm.

Question 30.
What is the difference between conducting hearing loss and neuro sensory hearing loss.
Answer:

Question 31.
Give short notes on melanin.
Answer:

• Melanocytes synthesize melanin.
• It gives colour to skin and protects it from the sun.
• Vitiligo is a condition in which the melanin pigment is lost from the areas of the skin causing white patches.
• The leukoderma appears when melanocytes fails to synthesis melanin pigment.

Question 32.
What is meant by the proprioception?
Answer:

• Balance is part of a sense called proprioception.
• It is the ability to sense the position orientation and movement of the body.

Question 33.
Which is the fastest renewable cells in the body? How is it affected?
Answer:
Taste buds

• Taste buds are subjected to huge amounts of friction because of their location and are routinely burned by hot foods.
• These cells are replaced every 7-10 days.

Question 34.
Name the disease which can affect people of any age gender or ethnic group. This is not the contagious disease?
Answer:
Leucoderma is a condition in which the melanin pigment is lost from areas of the skin causing white patches.

Question 35.
What are meissner’s corpuscles?
Answer:

• These are small light pressure receptors found just beneath the epidermis in the dermal papillae.
• They are numerous in hairless skin areas such as finger tips and soles of the feat.

(5 Marks)

IV. Brief Answers

Question 1.
Describe structure of a neuron.
Answer:
Neuron is composed of three region.

1. Cell body
2. Dendrites
3. axon.

Cell body:
The cell body is spherical. There is no centriole.
The plasma membrane covering the neuron is called neurilemma and axon is axolemma.

Dendrites:
The repeatedly branched short fibres coming out of the cell bod dendrites which transmit impulses towards the cell body in it’s cytoplasm Nissl’s granules are present.

Axon:
It is a long fibre that arises from a cone shaped area of the cell body. There is no golgi bodies and Nissis granules in its cytoplasm.
The axon of peripheral nerves is surrounded by Schwann’s cells to form myelin sheath. The myelin sheath is not continuous. There are gaps in the myelin sheath between an adjacent Schwann cells called nodes of Ranvier.
Each branch at the distal end of the axon terminates into a knob like structure called synaptic knob which possesses synaptic vesicles filled with transmitters. The axon transmits nerve impulses away from the body to neuro muscular junction. The myelinated nerve cell transmits impulses faster than non – myelinated nerve cells.

Question 2.
Describe about the different types of neuron with diagram?
Answer:
1. Multi polar neurons:
They have many processes with one axon and two or more dendrites.

2. Bipolar neurons:
They have two processes with one axon and one dendrites.
These are found in the retina of the eye, inner ear and the olfactory area of the brain.

3. Unipolar neurons:
They have a single short process and one axon.

Question 3.
Give an account of Ionic channels in the axolemma?
Answer:
Ionic channels:

1. Leakage channels
2.  Ligand – gated channels
3. Voltage-gated channels.

1. Leakage channels:

• • These channels are always remain open.
  • K⁺ leakage channels are more in number than the Na⁺ leakage channels.
  • Sarco lemma has greater permeability to k⁺ icons than Na⁺ icons
  • These icons keep moving continuously to maintain the potential continuously to maintain the
  • potential difference across the axo lemma.

2. Ligand – gated channels:
These are chemic called gated channels which open or close in response to a chemical stimuli.

• They are located between the pre synaptic membrane of the first axon and post synaptic membrane of the second.
• The neurotransmitter acetylcholine opens ligand channels that allow Na⁺ and Ca⁺⁺ ions diffuse inward and K⁺ icon diffuse outward.

Voltage-gated channels:
Answer:
This channels open in response to a physical stimulus in the form of vibration such as touch and pressure.

• Sodium Voltage gated channels.
• Potassium Voltage gated channels.

Question 4.
Give an account of resting potential?
Answer:

• The electrical potential difference across the plasma membrane of a resting neuron is called the resting potential.
• More potassium is getting out of the neurilemma rather than sodium which is getting into.
• Hence the interior of the cell becomes negative.
• In resting condition the axon membrane is more permeable to K⁺ and less permeable to Na⁺ cons whereas it remains impermeable to negatively charged protein icons.
• In the outer side of axon there is low concentration of K⁺ and high concentration of Na⁺ ions.
• This difference can be maintained by ATP – driven sodium – potassium pump. This exchange 3 Na⁺ outwards for 2K⁺ in the cells.
• In neuron the resting membrane potential ranges from 40mv to 90mv.
• And its normal value is 70mv.

Question 5.
a) What is meant by action – membrane potential?
b) What is Depolarisation?
Answer:
a) An action potential occurs when a neuron sends information down an axon away from the cell body.
b) When a nerve fibre is stimulated sodium voltage gate opens and makes the axo lemma permeable to Na⁺⁺ and the potassium voltage gate closes and potassium is getting out of the axo lemma. The concentration reduces

• The axo lemma becomes positively charged inside and negatively charged outside.
• This reversal of electrical charge is called depolarisation potential reaches level called threshold potential (-55mV)
• The stimulus which bring this threshold potential is called threshold stimulus.
• The action potential occur in response to a threshold stimulus but does not occur at subthreshold stimuli. This is called all or none principle.
• Due to the rapid influx of Na⁺ ions the membrane potential shoots rapidly up to +45mV which is called the spike potential.

Question 6.
What is synapsis?
Answer:

• The junction between two neurons is called a synapses through which a nerve impulse is transmitted,
• The first neuron involved in the synapse forms the pre synaptic neuron and the second neuron is the post – synaptic neuron
• A small gap between the two neuron is synaptic cleft.
• The axon terminals contain synaptic vesicles filled with neurotransmitters.
• When an impulse arrives at the axon terminals it depolorizes the pre – synaptic membrane opening the voltage gated calcium channels.
• Influx of calcium ions stimulates the synaptic vesicles toward the pre – synaptic membrane and fuse with it.
• In the neurilemma the vesicles release their neurotransmitters into the synaptic cleft by exocytosis.
• The released neurotransmitters bind to their specific receptors.
• The entry of the ions can generate a new potential in the post synaptic neuron.
• This excitatory post – synaptic potential causes depolarisation and in inhibitory post – synaptic potential causes hyperpolarisation.

Question 7.
In the following diagram indicate
Answer:
(A) – Frontal
(B) – parietal
(C) – occipital
(D) – temporal lobe

Question 8.
Describe the structure of human brain with a diagram?
Answer:

• The brain is located in the cranial cavity and it is covered by three cranial membranes.
• The outer layer — durameter the inner most layer piameter and the median thin layer arachnoid. The brain is divided into three major regions. Fore brain, Mid-brain, Hind

• It comprises of cerebrum and diencephalon.
• Tire cerebral cortex is composed of grey and unmyelinated nerve cells.
• The medulla is composed of white mater.
• The surface of the cerebrum shows many convolutions and grooves. The folds are called gyri and the shallow groove is sulci.

There are eight lobes in cerebrum.
A pair of frontals, parietals temporals and occipital lobes.
The longitudinal fissure divides the cerebrum | longitudinally into two hemispheres The hemispheres are connected by a tract of nerve fibres called corpus callosum.
Cerebral cortex has three functional areas

Sensory areas :
It occurs in the parietal temporal and occipital lobes of the cortex.

Motor areas :
This controls voluntary muscular movement which lies in the posterior part of the frontal iobes.

Association area :
It lies in between cortex and diencephalan This involves in memory communication learning and reasoning.

Question 9.
Describe the structure of hind brain?
Answer:
Rhombencephalon forms the hind brain.
It comprises of cerebellum pons varolii and medulla oblongata.

Cerebellum:
It is the second largest part of the brain. It consists of two cerebellar hemisphere and central worm shaped part the vermis.

Function:
It controls and coordinates muscular movements and body equilibrium.
Any damage to cerebellum results in unco-ordinated voluntary muscle movements.

Pons varoli:
It lies in between the midbrain and the medulla oblongata.
This form a bridge between the two cerebellar hemisphere and connect the medulla oblongata with the other region of the brain.

Medulla oblongata:
This forms the posterior most part of the brain. It connects the spinal cord with various parts of the brain.
It receives and integrates signals from spinal cord and sends it to the cerebellum and thalamus.

Function:
It controls cardiovascular reflexes respiration and gastric secretions.

Question 10.
Describe the structures of diencephalon?
Answer:
Epithalamus

• It is a non – nervous tissue.
• The anterior part of epithalamus is vascular and folded to form the anterior choroid plexus.
• The epithalamus forms a short stalk which ends in a rounded body called pineal body.
• This secretes the hormone melotonin which regulates sleep and wake cycle.

Thalamus

• It is formed of grey matter
• It serves as a relay centre for impulses between the spinal cord brain stem and cerebrum.
• It plays a key role in learning and memory.
• It is a major co-ordinating centre for sensory and motor signalling.

Hypothalamus

• It forms the floor of the diencephalon.
• It has a pair of small rounded body called mammillary bodies
• It involves in olfactory reflexes and emotional responses to odour.
• It maintains homeostasis.
• It controls the body temperature.
• Urge for eating and drinking.
• It also contains a group of neuro secretory cells which secrete the hypothalamic hormones.
• It also acts as the satiety centre.

Question 11.
Give an account of ventricles of the brain.
Answer:

• The brain has four hollow fluid filled spaces.
• The c – shaped space found inside each cerebral hemisphere forms the lateral ventricles I and II which are separated by a thin membrane called the septum pellucidum. Each lateral ventricle communicates with the III ventricle through opening called foramen of mortro.
• The III ventricle opens in to the IV th ventricle through a canal called aqueduct of sylvius. Choroid plexus is a network of blood capillaries found in the root of the ventricles and forms cerebro spinal fluid.

Functions

• CSF provides buoyancy to the CNS.
• It acts as a shock absorber.
• It nourishes the brain by supplying food and oxygen.
• It carries harmful metabolic wastes from the brain to the blood.
• It maintains a constant pressure inside the cranial vessels

Question 12.
Differentiate the conditioned stimulus from unconditioned stimulus.
Answer:

Question 13.
Tabulate the nerves and functions and its nature of 6-12th cranial nerves.
Answer:

Question 14.
Tabulate the functions of sympathetic and para sympathetic nerve.
Answer:

Question 15.
Describe the structure of cross section of spinal cord.
Answer:

• There are two indentations the posterior median sulcus and the anterior median fissure.
• In the spinal cord the grey matter forms an inner butterfly shaped region surrounded by the outer white matter.
• The grey matter consists of dendrites inter neurons and guai cells.
• White matter consists of bundles of nerve fibres.
• Each half of the grey matter is divided into a
• Dorsal horn – Cell bodies of inter neurons.
• Ventral horn – Efferent motor neurons supplying the skeletal muscle.
• Lateral horn – Nerves supply to heart smooth muscles exocrine glands. Originate from the cell bodies.
• Ascending tract – This carry sensory impulses to the brain.
• Descending tract – This carry motor impulses to brain.

Question 16.
Give an account of the functional components of a reflex arc.
Answer:
Sensory receptor – It is a sensory structure that responds to specific stimulus.
Sensory neuron – This neuron takes the sensory impulse to the grey (afferent) matter of the
spinal cord through the dorsal root of the spinal cord.
Inter neuron – It may serve to transmit the impulses from the sensory neuron to the motor neuron.
Motor neuron – It transmits impulse from CNS to the effector organ
Effector neuron – It may be a muscle or gland which responds to the impulse received.

• Lacrymal glands located in the upper lateral region of each orbit secrete tears.
• Tears are secreted at the rate of 1 ml/day.
• Tears contain salt mucus and lysozyme enzyme to destroy bacteria.
• The protective mucus membrane present in the outer surface of the eye ball.
• The eye has two compartments anterior and posterior compartments filled with aqueous humour and vitreous humour respectively.
• The eye ball is consists of three layers sclera, vascular choroid and sensory retina.

Sclera

• It consists of anterior cornea and the posterior sclera.
• Cornea is composed of stratified squamous epithelium. Sclera forms the white of the eye and protects the eyeball.
• At the junction of the sclera and the cornea is a channel called canal of schlemm which continuously drains out the excess of aqueous humour.

Choroid layer
It is highly vascularised pigmented layer.

Question 17.
Tabulate the differences between sympathetic and parasympathetic neural system.
Answer:

Question 18.
Give an account of peripheral nervous system.
Answer:

• All nervous tissue outside the central nervous system is the peripheral neural system.
• It includes nerves ganglia enteric plexuses and sensory receptors.
• Ganglia are sinai! masses of nervous tissue.
• The neurons of these plexuses help in regulating the digestive system.
• The specialised structure that helps to respond to changes in the environment are called sensory receptor.
• This triggers nerve impulses along the afferent fibres to CNS.
• PNS comprises of 12 pairs of cranial nerves and 31 pairs of spinal nerve.
• The neural retina layer consists of cones and rods.
• The yellow flat spot at the centre of the posterior region of the retina is called macula lutea.
• A small depression present in the centre of the

Question 19.
Describe the structure of an eye.
Answer:

• Eye is located in the orbit of the skull and held in its position with the help of six-extrinsic muscles.
• Eye lashes and the eye brows help to protect the eyeballs.
• Anteriorly the choroid thickens to form the ciliary body and coloured portion of the iris.
• The aperture at the centre of the iris is the pupil through which the light enters.
• The ability of the eyes to focus objects at varying distances is called accommodation which is achieved by suspensory ligament ciliary muscle and ciliary body.

Retina

• It contains two region.
• A sheet of non visual pigmented part neural visual region.
• yellow spot is called fovea centralis which contains only cones.
• The optic nerves and the retinal blood vessels enter the eye slightly below the posterior pole which is devoid of photo receptors called blind spot.

Question 20.
Draw the diagram of cross section of the eye.
Answer:

Question 21.
Describe about the mechanism of vision.
Answer:

• When light enters the eye it gets refracted by the cornea, aqueous humor and lens and it is focused on the retina and excites the rod and cone cells.
• The rods and cones contain the retinal a derivative of vitamin A and the photo pigment opsin.
• Light induces dissociation of retinal from opsin and causes the structural changes in opsin.
• This generates an action potential in the photo receptor cells.
• It is transmitted by the optic nerves to the visual cortex of the brain via the optic nerves for the perception of vision.

Question 22.
List the refractive errors of eye.
Answer:
Myopia

• The affected person cannot see distant objects.
• As the eyeball is elongated or thickened lens the image of distant object is formed in front of the yellow spot.
• This error can be corrected using concave lens.

Hyper metropia

• Affected person cannot see the nearby objects.
• This is due to a shortened eyeball and thin lens. So the image of closest object is converged behind the retina.
• This defect can be corrected by using convex lens.

Presbyopia

• Due to aging the lens loses elasticity and power of accommodation.
• Convex lenses are used to correct this defect.

Astigmatism

• It is due to the rough curvature of cornea or lens.
• Cylindrical glasses are used to correct this error.

Question 23.
Describe the structure of an ear?
Answer:
Anatomically the ear is divided into three regions external ear middle ear and inner ear.
External ear:-

• It consists of pinna external auditory meatus and ear drum.
• The pinna collects the sound waves.
• The external auditory meatus extends up to the tympanic membrane.
• The tympanic membrane is covered with skin outside and with mucus membrane inside.

Middle ea:-

• It is a air filled cavity in the temporal bone.
• The middle ear contains three ossicles malleus incus and stapes.
• The malleus is attached to the tympanic membrane and its head articulates with the incus.
• The stapes is attached to the oval window in the inner ear.
• The Eustachian tube connects the middle ear cavity with the pharynx

Inner ear:-

• It is the fluid filled cavity consisting of two parts the bony labyrinth and the membranous labyrinths.
• The bony labyrinth consists of three areas, cochlea, vestibule and semicircular canals.

a Cochlea is a coiled portion consist of 3 chambers namely.

1. Scala vestibule
2. Scala media
3. Scala tympanii.

Scala vestibule and scala tympani are filled with peri lymph.
The scala media is filled with endo lymph.

Question 24.
Describe the structure and functions of organ of cortii.
Answer:

• Organ of corti is a sensory ridge located on the top of the basilar membrane.
• Basilar membrane contains numerous hair cells that are arranged in four rows.
• Protruding from the apical part of each hair cell is hair like structures known as stereocilia.
• On the organ of cortii a stiff gel membrane called tectorial membrane is situated.
• During the conduction of sound wave sterocilia makes contact with tectorial membrane.

Question 25.
Give an account of mechanism of sound?
Answer:

• Sound waves entering the external auditory meatus fall on the tympanic membrane and gets vibrated.
• These vibrations are transmitted to the oval window through the three ear ossicles.
• Since tympani membrane is 17-20 times larger than the oval windows. This pressure exerted on the oval window is about 20 times more than that on the tympanic membrane.
• This pressure causes the round window to alternately bulge outward and inward mean while the basilar membrane along with the organ of corti move up and down.
• These movements of hair alternately open and close the mechanically gated ion channel causes action potential.
• This is propagated to the brain as sound sensation through cochlear nerve.

Question 26.
Differentiate the rods from cones.
Answer:

Question 27.
A man is chating with his family in this time a house fly sits on his back at once he lifts the hand and strikes the fly. How can he know that? What are the structures involved in this perception?
Answer:

• The skin senses this skin is the largest sense organ.
• All over the skin sensory receptors of pressure heat cold and pain.
• Following are the sensory receptors of skin.

Tactile merkel disc

• It is a light touch receptor lying in the deeper layer of epdidermis.
• Hair follicle receptors. These are light touch receptors lying around the hair follicles.

Meissner’s corpuscles

• These are small light pressure receptors found just beneath the epidermis in the dermal papillae.
• They are numerous in hair less skin areas such as finger tips and soles of the feet.

Pacinian corpuscles

• These are the large egg shaped receptors found scattered in the dermis.
• It detects different textures temperature hardness and pain.

Ruffini endings
This lie in the dermis responds to continuous pressure Krause end bulbs are thermo receptors that sense temperature.

Question 28.
Give notes on Defects of ear.
Answer:

• Deafness may be temporary or permanent
• Conductive deafness
• Possible causes
• The blockage of ear canal with ear wax.
• Rupture of ear drum.
• Middle ear infection with fluid accumulation,
• Restriction of ossicular movement.
• Sensory-neural deafness
• The defect may be in the organ of cortii or the auditory nerve or in the ascending auditory pathways or auditory cortex.

Question 29.
a) What is meant by proprioception?
b) Give an account of organs of equilibrium?
Answer:
The ability to sense the position orientation and movement of the body is called proprioception.
1. Vestibular system: This is the organ of balance.
It is composed of a series of fluid filled sacs contain endolymph and are kept in the surrounding peri lymph.

Semicircular canals

• The canals that lie posterior and lateral to the vestibule are semi circular canals.
• At each end of semi circular canal has a swollen area called ampulla.
• Each ampulla has a sensory area known as crista ampullaris.
• It detects the rotational movement of the head.

Question 30.
Give notes on Gustatory receptors?
Answer:

• The sense of taste is considered to be the most pleasurable of all senses.
• The tongue is provided with many small projections called papillae which gives the tongue an abrasive feel.
• Most taste buds are located on the tongue few are scattered on the soft palate inner surface of the cheeks.

Structure
Taste buds are flask shaped and consists of 50 -100 epithelial cells of two major types.

1. ustatory epithelial cells: Taste cells.
2. Basal epithelial cells

Gustatory epithelial cells:

• Long gustatory hairs project from the tip of the gustatory cells and extends through a taste pore senses the taste.
• The sensory dendrites send signal to the brain and senses the taste.
• The basal cells differentiates in to new gustatory cells.

Question 31.
Describe the structure of the receptor involved with a diagram.
Answer:

• Taste buds are flask shaped. There are two major types.
• Gustatory epithelial cells or taste cells.
• Basal epithelial cells or repairing cells.
• Long micro villi called gustatory hairs project from the tip of the gustatory cells and extends through a taste pore to the surface of the epithelium.
• Gustatory hairs are tire sensitive portion of the gustatory cells and they have sensory dendrites which send the signal to the brain.
• The basal cells that act as stem cells divide and differentiate into new gustatory cells.

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Chemistry Guide Pdf Chapter 12 Basic Concepts of Organic Reactions Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Chemistry Solutions Chapter 12 Basic Concepts of Organic Reactions

11th Chemistry Guide Basic Concepts of Organic Reactions Text Book Back Questions and Answers

Textbook Evaluation:

I. Choose the best answer:

Question 1.
For the following reactions
(A) CH₃CH₂CH₂Br + KOH → CH₃ – CH = CH₂ + KBr + H₂O

(B) (CH₃)₃CBr + KOH → (CH₃)₃COH + KBr

(C)
Which of the following statement is correct?
a) (A) is elimination, (B) and (C) are substitution
b) (A) is substitution, (B) and (C) are elimination
c) (A) and (B) are elimination and (C) is addition reaction
d) (A) is elimination, (B) is substitution and (C) is addition reaction
Answer:
d) (A) is elimination, (B) is substitution and (C) is addition reaction

Question 2.
What is the hybridisation state of benzyl carbonium ion?
a) sp²
b) spd²
c) sp³
d) sp²d
Answer:
a) sp²

Question 3.
Decreasing order of nucleophilicity is
a) OH^– > NH₂^– > -OCH₃ > RNH₂
b) NH₂^– > OH^– > -OCH3 > RNH₂
c) NH₂^– > CH₃O^– > OH^– > RNH₂
d) CH₃O^– > NH₂^– > OH^– > RNH₂
Answer:
b) NH₂^– > OH^– > -OCH3 > RNH₂

Question 4.
Which of the following species is not electrophilic in nature?
a) Cl⁺
b) BH₃
c) H₃O⁺
d) ⁺NO₂
Answer:
c) H₃O⁺

Question 5.
Homolytic fission of covalent bond leads to the formation of
a) electrophile
b) nucleophile
c) carbocation
d) free radical
Answer:
d) free radical

Question 6.
Hyper conjucation is also known as
a) no bond resonance
b) Baker – nathan effect
c) both (a) and (b)
d) none of these
Answer:
c) both (a) and (b)

Question 7.
Which of the group has highest + I effect?
a) CH₃–
b) CH₃ – CH₂ –
c) (CH₃)₂ – CH-
d) (CH₃)₃ – C –
Answer:
d) (CH₃)₃ – C –

Question 8.
Which of the following species does not exert a resonance effect?
a) C₆H₅OH
b) C₆H₅Cl
c) C₆H₅NH₂
d) C₆H₅NH₃
Answer:
d) C₆H₅NH₃

Question 9.
– I effect is shown by
a) – Cl
b) – Br
c) both (a) and (b)
d) – CH₃
Answer:
c) both (a) and (b)

Question 10.
Which of the following carbocation will be most stable?
a) Ph₃⁺C –
b) CH₃ – ⁺CH₂ –
c) (CH₃)₂ – ⁺CH
d) CH₂ = CH – ⁺CH₂
Answer:
d) CH₂ = CH – ⁺CH₂

Question 11.
Assertion:
Tertiary Carbocations are generally formed more easily than primary Carbocations ions.
Reason:
Hyper conjucation as well as inductive effect due to additional alkyl group stabilize tertiary carbonium ions.
a) both assertion and reason are true and reason is the correct explanation of assertion.
b) both assertion and reason are true but reason is not the correct explanation of assertion.
c) assertion is true but reason is false.
d) both assertion and reason are false.
Answer:
a) both assertion and reason are true and reason is the correct explanation of assertion.

Question 12.
Heterolytic fission of C – Br bond results in the formation of
a) free radical
b) Carbanion
c) Carbocation
d) Carbanion and Carbocation
Answer:
d) Carbanion and Carbocation

Question 13.
Which of the following represent a set of nucleophiles?
a) BF₃, H₂O, NH^2-
b) AlCl₃, BF₃, NH₃
c) CN, RCH₂^–, ROH
d) H⁺, RNH₃⁺, :CCl₂
Answer:
c) CN, RCH₂^–, ROH

Question 14.
Which of the following species does not acts as a nucleophile?
a) ROH
b) ROR
c) PCl₃
d) BF₃
Answer:
d) BF₃

Question 15.
The geometrical shape of carbocation is
a) Linear
b) tetrahedral
c) Planar
d) Pyramidal
Answer:
c) Planar

II. Write brief answer to the following questions:

Question 16.
Write short notes on
a) Resonance
b) Hyper Conjucation
Answer:
a) Resonance (or) Mesomeric effect:
The resonance is a chemical phenomenon which is observed in certain organic compounds possessing double bonds at a suitable position. Certain organic compounds can be represented by more than one structure and they differ only in the position of bonding and lone pair of electrons. Such structures are called resonance structures (canonical structures) and this phenomenon is called resonance. This phenomenon is also called mesomerism or mesomeric effect.

For example, the structure of aromatic compounds such as benzene and conjugated systems like 1,3 – butadiene cannot be represented by a single structure, and their, observed properties can be explained on the basis of a resonance hybrid.

In 1,3 butadiene, it is expected that the bond between C¹ – C² and C³ – C⁴ should be shorter than that of C² – C³, but the observed bond lengths are of same. This property cannot be explained by a simple structure in which two n bonds localised between C¹ – C² and C³ – C⁴. Actually the n electrons are delocalised as shown below.

The resonating structures are called canonical forms and the actual structure lies between these three resonating structures, and is called a resonance hybrid. The resonance hybrid is represented as below.

Similar to the other electron displacement effect, mesomeric effect is also classified into positive mesomeric effect (+M or +R) and negative mesomeric effect (-M or -R) based on the nature of the functional group present adjacent to the multiple bond.

b) Hyper Conjucation:
The delocalisation of electrons of a bond is called as hyper conjugation. It is a special stabilising effect that results due to the interaction of electrons of a σ -bond (usually C – H or C – C) with the adjacent, empty non-bonding p-orbital or an anti¬bonding σ* or π*-orbitals resulting in an extended molecular orbital. Unlike electromeric effect, hyper conjugation is a permanent effect.

It requires an α-CH group or a lone pair on atom like N, O adjacent to a π bond (sp² hybrid carbon). It occurs by the overlapping of the σ-bonding orbitai or the orbital containing a lone pair with the adjacent π-orbital or p-orbital.

Example:
In propene, the σ -electrons of C-H bond of methyl group can be delocalised into the π -orbital of doubly bonded carbonas represented below.

In the above structure the sigma bond is involved in resonance and breaks in order to supply electrons for delocalization giving rise to 3 new canonical forms. In the contributing canonical structures: (Il), (III) & (IV) of propene, there is no bond between an α-carbon and one of the hydrogen atoms. Hence the hyper conjugation is also known as “no bond resonance” or “Baker Nathan effect”. The structures (II), (III) & (IV) are polar in nature.

Question 17.
What are electrophiles and nucleophiles? Give suitable examples for each.
Answer:
Nucleophiles are reagents that has high affinity for electron positive centers. They possess an atom has an unshared
pair of electrons, and hence it is in search for an electro positive centre where it can have an opportunity to share its electrons to form a covalent bond, and gets stabilised. They are usually negatively charged ions or electron rich neutral molecules (contains one or more lone pair of electrons). All Lewis bases act as nucleophiles.
Example :
Ammonia(NH₃) and amines (RNH₂), water (H₂O), alcohols (ROH) and ethers ((R-O-R)

Electrophiles:
Electrophiles are reagents that are attracted towards negative charge or electron rich center. They are either positively charged ions or electron deficient neutral molecules. All Lewis acids acts as electrophiles. Neutral molecules like SnCl4 can also act as an electrophile, as it has vacant d – orbitals which can accommodate the electrons from others.
Example:
Carbon dioxide (CO₂), dichlorocarbene (: CCl₂), Aluminium chloride (AlCl₃), boron trifluoride (BF₃) and Ferric Chloride (FeCl₃)

Question 18.
Show the heterolysis of covalent bond by using curved arrow notation and complete the following equations. Identify the nucelophile in each case.
i) CH₃ – Br + KOH →
ii) CH₃ – O – CH₃ + HI →
Answer:
(i) CH₃ – Br + KOH →
CH₃ – Br + KQH → CH₃OH + KBr
Nucleophile is : OH^–

ii) CH₃ – O – CH₃ + HI →
H            I
CH₃ – O – CH₃ + HI → CH₃OH + CH₃ I
Nucleophile is : I^–

Question 19.
Explain inductive effect with suitable example.
Answer:
Inductive effect is defined as the change in the polarisation of a covalent bond due to the presence of adjacent bonds, atoms or groups in the molecule. This is a permanent phenomenon.

Let us explain the inductive effect by considering ethane and ethylchloride as examples. The C-C bond in ethane is non polar while the C-C bond in ethyl chloride is polar. We know that chlorine is more electronegative than carbon, and hence it attracts the shared pair of electron between C-Cl in ethyl chloride towards itself. This develops a slight negative charge on chlorine and a slight positive charge on carbon to which chlorine is attached.

To compensate it, the C₁ draws the shared pair of electron between itself and C₂ This polarisation effect is called inductive effect. This effect is greatest for the adjacent bonds, but they also be felt farther away. However, the magnitude of the charge separation decreases rapidly, as we move away from C₂ and is observed maximum for 2 carbons and almost insignificant after 4 bonds from the active group.

It is important to note that the inductive effect does not transfer electrons from one atom to another but the displacement effect is permanent. The inductive effect represents the ability of a particular atom or a group to either withdraw or donate electron density to the attached carbon. Based on this ability the substituents are classified as +I groups and -I groups. Their ability to release or withdraw the electron through sigma covalent bond is called +I effect and -I effect respectively.

Highly electronegative atoms and atoms of groups which are cany a positive charge are electron withdrawing or-I group.
Example :
-F , -Cl, -COOH, -NO₂ NH₂

Higher the electronegativity of the substituent, greater is the -I effect. The order of the -I effect of some groups are given below.
NH₃ > NO₂ > CN > SO₃H > CHO > CO > COOH > COCl > CONH₂ > F > Cl > Br > I > OH > OR > NH₂ > C₆H₅ > H

Highly electropositive atoms and atoms are groups which carry a negative charge are electron donating or +1 groups.
Example:
Alkali metals, alkyl groups such as methyl, ethyl, negatively charged groups such as CH₃O^–, C₂H₅O^–, COO^– etc.

Lesser the electronegativity of the elements, greater is the +1 effect. The relative order of +1 effect of some alkyl groups is given below.
-C(CH₃)₃ > -CH(CH₃)₂ > -CH₂CH₃ > -CH₃

Question 20.
Explain electromeric effect with suitable example.
Answer:
Electromeric is a temporary effect which operates in unsaturated compounds (containing > C = C <, > C = 0, etc…) in the presence of an attacking reagent.
Let us consider two different compounds.
(i) compounds containing carbonyl group ( > C = O)
(ii) unsaturated compounds such as alkenes ( > C = C < )

When a nucleophile approaches the carbonyl compound, the n electrons between C and O is instantaneously shifted to the more electronegative oxygen. This makes the carbon electron deficient and thus facilitating the formation of a new bond between the incoming nucleophile and the carbonyl carbon atom.

On the other hand when an electrophile such as H⁺ approaches an alkene molecule, the π electrons are instantaneously shifted to the electrophile and a new bond is formed between carbon and hydrogen. This makes the other carbon electron deficient and hence it acquires a positive charge.

The electrometric effect, is denoted as E effect. Like the inductive effect, the electrometric effect is also classified as + E and – E based on the direction in which the pair of electron is transferred to form a new bond with the attacking agent.

When the π electron is transferred towards the attacking reagent, it is called + E (positive electrometric) effect.

The addition of H+ to alkene as shown above is an example of +E effect.
When the n electron is transferred away from the attacking reagent, it is called, -E (negative electrometric) effect.

The attack of CN^– on a carbonyl carbon, as shown above, is an example of – E effect.

Question 21.
Give examples for the following types of organic reactions
(i) β – elimination
(ii) Electrophilic substitution
Answer:
(i) β – elimination:
In this reaction two substituents are eliminated from the molecule, and a new C – C double bond is formed between the carbon atoms to which the eliminated atoms/groups are previously attached. Elimination reaction is always accompanied with change in hybridisation.
Example:
n – Propyl bromide on reaction with alcoholic KOH gives propene. In this reaction hydrogen and Br are eliminated.

(ii) Electrophilic substitution:

Here, Y⁺ is an electrophile.
Example :
Nitration of Benzene

11th Chemistry Guide Basic Concepts of Organic Reactions Additional Questions and Answers

I. Choose the best answer:

Question 1.
In organic reactions the reactant is called as ______.
a) intermediate
b) product
c) substrate
d) by product
Answer:
c) substrate

Question 2.
Heterolysis of C – Cl bond produces
a) Two free radicals
b) Two carbonium ions
c) Two carbanions
d) One cation and one anion
Answer:
d) One cation and one anion

Question 3.
Heterolysis of propane gives
a) Methyl and ethyl free radicals
b) Methyl carbocation and ethyl free radicals
c) Methyl anion and ethyl carbocation
d) Methyl free radical and ethyl carbocation
Answer:
c) Methyl anion and ethyl carbocation

Question 4.
Removal of hydride ion from a methane molecule will give a
a) Methyl radical
b) Carbonium ion
c) Carbanion
d) Methyl group
Answer:
b) Carbonium ion

Question 5.
The shape of carbonium ion is
a) Planar
b) Linear
c) Pyramidal
d) Tetrahedral
Answer:
a) Planar

Question 6.
The shape of methyl free radicals is
a) Planar
b) Pyramidal
c) Tetrahedral
d) Linear
Answer:
a) Planar

Question 7.
The reaction, (CH₃)₃C – Br -» (CH₃)₃ C⁺ + Br is an example of
a) Homolytic fission
b) Heterolytic fission
c) Cracking
d) All the above
Answer:
b) Heterolytic fission

Question 8.
Which of the following contains only three pairs of electrons
a) Carbocation
b) Carbanion
c) Free radical
d) All of these
Answer:
a) Carbocation

Question 9.
Which of the following species is paramagnetic
a) A carbaonium ion
b) A free radical
c) A carbanion
d) All of these
Answer:
b) A free radical

Question 10.
In carbonium ion the carbon bearing the positive charge is
a) sp hybridized
b) sp² hybridized
c) sp³ hybridized
d) un hybridized
Answer:
b) sp² hybridized

Question 11.
Among the following the true property about
is
a) non – planar
b) C⁺ is sp² – hybridized
c) Electrophile can attack on C⁺
d) Does not undergo hydrolysis
Answer:
b) C⁺ is sp² – hybridized

Question 12.
The geometry of a methyl carbanion is likely to be
a) Pyramidal
b) Tetrahedral
c) Planar
d) Linear
Answer:
a) Pyramidal

Question 13.
Which of the following statements are correct for nucleophile?
a) All negatively charged species are nucleophiles
b) Nucleophiles are Lewis bases
c) Alkenes, alkynes, benzene and pyrrole are nucleophiles
d) All are correct
Answer:
d) All are correct

Question 14.
Which one of the following statement is not correct for electrophile?
a) Electron deficient species are electrophiles
b) Electrophiles are Lewis acids
c) All positively charged species are electrophiles
d) AlCl₃ and SO₃ are electrophiles
Answer:
c) All positively charged species are electrophiles

Question 15.
Electrophiles are
a) Lewis bases
b) Lewis acids
c) Amphoteric
d) All of these
Answer:
b) Lewis acids

Question 16.
Electrophiles are
a) Electron loving species
b) Electron hating species
c) Nucleus loving reagents
d) Nucleus hating reagents
Answer:
a) Electron loving species

Question 17.
Nucleophiles are
a) Electron loving
b) Electron hating
c) Nucleus loving
d) Nucleus hating
Answer:
c) Nucleus loving

Question 18.
Which of the following statement is false about an electrophile?
a) Electron – deficient species
b) An acidic reagent
c) A reagent which attacks an electron – deficient site in a molecule
d) A species which seeks a pair of electrons
Answer:
c) A reagent which attacks an electron – deficient site in a molecule

Question 19.
Methyl carbanium ion is
a) Electrophile
b) Lewis acid
c) Nucleophile
d) Both (a) and (b)
Answer:
c) Nucleophile

Question 20.
Ammonia molecule is
a) A nucleophile
b) An electron deficient
c) A electrophile
d) An acid
Answer:
a) A nucleophile

Question 21.
Methyl carbanion is
a) Electrophile
b) Lewis acid
c) Both (a) and (b)
d) Nucelophile
Answer:
d) Nucelophile

Question 22.
Which of the following statements is correct about inductive effect?
a) Implies the transfer of lone pair of electrons from more electronegative atom to lesser electronegative atom in a molecule.
b) Implies the transfer to lone pair of electrons from lesser electronegative atom to the more electronegative atom in a molecule
c) Increases with increase in distance
d) Implies the atoms ability to cause bond polarization
Answer:
d) Implies the atoms ability to cause bond polarization

Question 23.
The displacement of electrons in a multiple bond in the presence of attacking reagent is called
a) inductive effect
b) electromeric effect
c) resonance
d) Hyper-conjugation
Answer:
b) electromeric effect

Question 24.
The electromeric effect in organic compounds is a
a) Temporary effect
b) Permanent effect
c) Temporary or permanent effect
d) All of the above
Answer:
a) Temporary effect

Question 25.
Which of the following is not the correct condition for resonance?
a) The positions of all the atomic nuclei in the resonating structures may be differ
b) The resonating structures must have the same number of unpaired or paired electrons
c) The molecules exhibiting resonance must be planar in nature
d) The resonating structures must have nearly the same energies
Answer:
a) The positions of all the atomic nuclei in the resonating structures may be differ

Question 26.
Resonance is due to ______.
a) delocalization of sigma electrons
b) migration of H atoms
c) migration of proton
d) delocalization of pi electrons
Answer:
d) delocalization of pi electrons

Question 27.
Resonance in benzene is accompanied by delocalization of n – electrons. Each n electron is attached with
a) 4 carbons
b) 2 carbons
c) 3 carbons
d) 6 carbons
Answer:
d) 6 carbons

Question 28.
Reaction mechanism describes
a) Sequential account of each step describing the details of electron movement
b) energy changes during bond breaking and bond formation
c) kinetics of the reaction
d) all of these
Answer:
d) all of these

Question 29.
Substitution reaction may be
a) Free radical substitution
b) Nucleophilic substitution
c) Electrophilic substitution
d) All are correct
Answer:
d) All are correct

Question 30.
CH₃ – CH₂ – X + KOH_(alc) → CH₂ = CH₂ + KX + H₂O is
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
c) elimination reaction

Question 31.
CH₄ + Cl₂ CH₃Cl + HCl is an example
for
a) free radical substitution reaction
b) electrophilic substitution reaction
c) nucleophile substitution reaction
d) nueclophilic addition reaction
Answer:
a) free radical substitution reaction

Question 32.
C₆H₆ + 3 Cl₂ C₆H₆Cl
a) free radical substitution reaction
b) electrophilic addition reaction
c) free radical addition reaction
d) nueclophilic addition reaction
Answer:
c) free radical addition reaction

Question 33.
Which one of the following orders is correct regarding the – I effect of the substituents?
a) – NR₂ < – OR > – F
b) -NR₂ > – OR > – F
c) -NR₂ < – OR< – F
d) -NR₂ > – OR < – F
Answer:
c) -NR₂ < – OR< – F

Question 34.
Decreasing – I power of given groups is
(1) -CN
(2) -NO₂
(3) – NH₃⁺
(4) -F
a) 2 > 1 > 4 > 3
b) 2 > 3 > 4 > 1
c) 3 > 2 > 4 > 1
d) 3 > 2 > 1 > 4
Answer:
d) 3 > 2 > 1 > 4

Question 35.
Which of the following belongs to – I group?
a) – C₆H₅
b) – CH₃
c) – CH₂CH₃
d) – C (CH₃)₃
Answer:
a) – C₆H₅

Question 36.
Which of the following functional group shows + R effect?
a) – CHO
b) – NO₂
c) -CN
d) – NR₂
Answer:
d) – NR₂

Question 37.
Hyper conjugation is
a) σ – π conjugation
b) Due to delocalization of σ and π bonds
c) No bond resonance
d) All of these
Answer:
d) All of these

Question 38.
+ R power of the given groups
(1) -O^–
(2) – NH₂
(3) – OH
(4) – NHCOCH₃ in decreasing order is
a) 1 > 2 > 3 > 4
b) 4 > 3 > 2 > 1
c) 1 > 3 > 2 > 4
d) 1 > 4 > 3 > 2
Answer:
a) 1 > 2 > 3 > 4

Question 39.
In pyridine:

Number of conjugated electrons are:
a) 6
b) 8
c) Zero
d) 5
Answer:
a) 6

Question 40.
In hyper conjugation, the atom involved is
a) β – H atom
b) α – H atom
c) γ – H atom
d) All
Answer:
b) α – H atom

Question 41.
Hyper conjugation involves overlap of the following orbtials
a) σ – σ
b) σ – p
c) p – p
d) π – π
Answer:
b) σ – p

Question 42.
+ I effect is shown by
a) – NO₂
b) – Cl
c) – Br
d) – CH₃
Answer:
d) – CH₃

Question 43.
Zero inductive effect is exerted by
a) C₆H₅ –
b) – H
c) CH₃ –
d) – Cl
Answer:
b) – H

Question 44.
Hyper conjugation is most useful for stabilizing which of the following carbocations?
a) neo – Pentyl
b) tert – Butyl
c) iso – Propyl
d) Ethyl
Answer:
b) tert – Butyl

Question 45.
Hyper conjugation phenomenon is possible in
a) H₂C = CH₂
b) CH₃CH₂ – CH = CH₂
c) C₆H₅CH = CH₂
d) (CH₃)₃C – CH = CH₂
Answer:
b) CH₃CH₂ – CH = CH₂

Question 46.
Among the following carbocations which is more stable
a) (C₆H₅)₃C⁺
b)
c)
d)
Answer:
a) (C₆H₅)₃C⁺

Question 47.
The compound which gives the most stable carbonium ion on dehydration
a)
b)
c) CH₃ – CH₂ – CH₂ – CH₂OH
d)
Answer:
b)

Question 48.
Which carbocation is more stable?

Answer:
a)

Question 49.
Arrange the following groups in order of decreasing – R (Or – M) power
(1) NO₂
(2) SO₃H
(3) CF₃
(4) CHO
a) 1 > 3 > 2 > 4
b) 1 > 2 > 3 > 4
c) 1 > 4 > 3 > 2
d)4 > 3 > 2 > 1
Answer:
a) 1 > 3 > 2 > 4

Question 50.
The reaction intermediate produced by homolytic cleavage of bond is called
a) carbocations
b) carbanions
c) free radicals
d) carbenes
Answer:
c) free radicals

Question 51.
Most stable carbocation is
a) CH₃ – ⁺CH₂
b) ⁺CH₂CHCl₂
c) ⁺CH₂CH₂Cl
d) ⁺CH₂ – CH₂NO₂
Answer:
a) CH₃ – ⁺CH₂

Question 52.
Carbocation is a reaction intermediate in which of the following reactions
a) E₁ reactions
b) Electrophilic addition reactions of alkenes and alkynes
c) S_N¹ reactions
d) All of the above
Answer:
d) All of the above

Question 53.
Halogenation of an alkane takes place through the intermediate
a) Carbocation
b) carbanion
c) carbon free radical
d) carbene
Answer:
c) carbon free radical

Question 54.
Which free radical is the most stable?

Answer:
a)

Question 55.
The most stable carbonium ion is
a) Methyl carbonium ion
b) Primary carbonium ion
c) Secondary carbonium ion
d) Tertiary carbonium ion
Answer:
d) Tertiary carbonium ion

Question 56.
Stability of which intermediate is not govern by hyperconjugation?
a) Carbon cation
b) carbon anion
c) carbon free radical
d) carboniumion
Answer:
b) carbon anion

Question 57.
Which of the following is an electrophilic reagent?
a) H₂O
b) OH^–
c) NO₂⁺
d) All of these
Answer:
c) NO₂⁺

Question 58.
CH₂ = CH₂ + Br₂ → CH₂Br – CH₂Br is an example for
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
a) addition reaction

Question 59.
R – X + OH^–_(aq) → R – OH + X⁺_(aq) is an example for
a) addition reaction
b) substitution reaction
c) elimination reaction
d) molecular rearrangement
Answer:
b) substitution reaction

Question 60.
C₆H₆ + Cl₂ C₆H₅Cl + HC1 is an example for
a) Free radical substitution reaction
b) Electrophilic substitution reaction
c) Nucleophilic addition reaction
d) Nucelophilic substitution reaction
Answer:
b) Electrophilic substitution reaction

Question 61.
Alkenes readily undergo
a) Substitution reactions
b) Addition reactions
c) Elimination reactions
d) Rearrangement reactions
Answer:
b) Addition reactions

Question 62.
Nitration of benzene is
a) nucleophilic substitution
b) nucleophilic addition
c) electrophilic substitution
d) free radical substitution
Answer:
c) electrophilic substitution

Question 63.
The reaction (CH₃)₃C – Br (CH₃)₃ C – OH is
a) elimination reaction
b) substitution reaction
c) free radical reaction
d) displacement reaction
Answer:
b) substitution reaction

Question 64.
Inductive effect involves
a) displacement of σ – electrons
b) delocalization of π – electrons
c) delocalization of σ – electrons
d) displacement of π – electrons
Answer:
b) delocalization of π – electrons

Question 65.
Compound which shows positive mesomeric effect
a) H₂C = CH – Cl
b) C₆H₅ – NO₂
c) H₂C = CH – CH₂Cl
d) both b & c
Answer:
a) H₂C = CH – Cl

Question 66.
The stability order, in the following carbocations,
CH₃CH₂⁺ (I), (CH₃)₂ ⁺CH (II), (CH₃)₃ C⁺ (III), ⁺CH₃ (IV)
a) I > IV > III > II
b) I > II > III > IV
c) III > IV > I > II
d) III > II > I > IV
Answer:
d) III > II > I > IV

Question 67.
Which is most stable carbocation?
a) n – propyl cation
b) iso – propyl cation
c) Ethyl cation
d) Triphenylmethyl cation
Answer:
d) Triphenylmethyl cation

Question 68.
Which one of the following carbanions is least stable?
a) CH₃CH₂^–
b) HC ≡ C^–
c) (C₆H₅)₃C^–
d) (CH₃)₃C^–
Answer:
d) (CH₃)₃C^–

Question 69.
Among the following, the strongest nucleophile is
a) C₂H₅SH
b) CH₃COO^–
c) CH₃NH₂
d) NCCH₂^–
Answer:
a) C₂H₅SH

Question 70.
Which of the following is least reactive in a nucleophile substitution reaction?
a) (CH₃)₃C – Cl
b) CH₂ = CHCl
c) CH₃CH₂Cl
d) CH₂ = CHCH₂Cl
Answer:
b) CH₂ = CHCl

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

Question 1.
What is mechanism of reaction?
Answer:
Many chemical reactions are depicted in one or more simple steps. Each step passes through an energy barrier, leading to the formation of short lived intermediates or transition states. The series of simple steps which collectively represent the chemical change, from substrate to product is called as the mechanism of the reaction. The slowest step in the mechanism determines the overall rate of the reaction.

Question 2.
What is Positive Mesomeric effect? Give example.
Answer:
Positive resonance effect occurs, when the electrons move away from substituent attached to the conjugated system. It occurs, if the electron releasing substituents are attached to the conjugated system. In such cases, the attached group has a tendency to release electrons through resonance. These electron releasing groups . are usually denoted as +R or +M groups.
Example:
– OH , – SH , – OR , – SR, – NH₂, – O – etc…

Question 3.
What is Negative Mesomeric effect? Give example.
Answer:
Negative resonance effect occurs, when the electrons move towards the substituent attached to the conjugated system. It occurs if the electron withdrawing substituents are attached to the conjugated system. In such cases, the attached group has a tendency to withdraw electrons through resonance. These electron withdrawing groups are usually denoted as -R or -M groups.
Example:
NO₂, > C = O, – COOH, – C ≡ N etc..

Question 4.
Explain hyper conjugate effect of vinyl chloride molecule.
Answer:
Hyper conjugation effect is also observed when atoms/groups having lone pair of electrons are attached by a single bond, and in conjugation with a π bond. The lone pair of electrons enters into resonance and displaces π electrons resulting in more than one structure.

Question 5.
What are the types of substitution reaction?
Answer:
In this reaction an atom or a group of atoms attached to a carbon atom is replaced by a new atom or a group of atoms. Based on the nature of the attacking reagent, these reactions can be classified as

• Nucleophilic substitution
• Electrophilic substitution
• Free radical substitution

Question 6.
Explain free radical substitution reaction with the suitable example.
Answer:

Aliphatic electrophilic substitution
A general aliphatic electrophilic substitution is represented as

Question 7.
Explain Nucleophilic Addition reaction with suitable example.
Answer:

Example:
Addition of HCN to acetaldehyde

Question 8.
Explain free radical addition reaction with suitable example.
Answer:
A general free radical addition reaction can be represented as below.


In the above reaction, Benzoyl perioxide acts as an radial initiator. The mechanism involves free radicals.

Question 9.
Write a note on Functional Group inter conversion.
Answer:
Organic synthesis involves functional group inter conversions. A particular functional group can be converted into other functional group by reacting it with suitable reagents. For example: The carboxylic acid group (-COOH) presents in organic acids can be transformed to a variety of other functional group such as – CH₂-OH, – CONH₂, – COCl by treating the acid with LiAlH₄, NH_3, and SOCl₂ respectively.

Question 10.
After cutting an apple it turn brown. Why?
Answer:
Apples contain an enzyme called polyphenol oxidase (PPO), also known as tyrosinase. Cutting an apple exposes its cells to the atmospheric oxygen and oxidizes the phenolic compounds present in apples. This is called the enzymatic browning that turns a cut apple brown. In addition to apples, enzymatic browning is also evident in bananas, pears, avocados and even potatoes.

III. Short answer questions (3 Marks):

Question 1.
Explain hybridization of carbon in carbocation.
Answer:
In a carbocation, the carbon bearing positive charge is sp² hybridised and hence it has a planar structure. In the reaction involving such a carbocation, the attack of a negatively charged species (nucleophiles) take place on either side of the carbocation as shown below.

Shape of carbocation

The carbanions are generally pyramidal in shape and the lone pair occupies one of the sp3 hybridized orbitais. An alkyl free radical may be either pyramidal or planar.

Shape of carbanion

Shape of Carbon radical

Question 2.
Write three types of electron movement in organic reaction.
Answer:

• lone pair becomes a bonding pair.
• bonding pair becomes a lone pair.
• a bond breaks and becomes another bond.

Type: 1
A lone pair to a bonding pair
Example:

Type: 2
A bonding pair to a lone pair
Example:

Type: 3
A bonding pair to an another bonding pair
Example:

Question 3.
Explain hyper conjugate effect of acrylonitrile.
Answer:
When electronegative atoms or group of atoms are in conjugation with a π – bond,they pull π – electrons from the multiple bond. In case of carbocations, greater the number of alky groups attached to the carbon bearing positive charge, greater is number of the hyper conjucate structure. thus the stability of various carbocations decreases in the order :
3° Carbocation > 2° Carbocation > 1° Carbocation.

Question 4.
What are the different types of organic reactions?
Answer:
Organic compounds undergo many number of reactions, however in actual sense we can fit all those reactions into the below mentiohed six categories.

1. Substitution reactions
2. Addition reactions
3. Elimination reactions
4. Oxidation and reduction reactions
5. Rearrangement reactions
6. Combination of the above

Question 5.
Explain nucleophilc substituion reaction with suitable example.
Answer:
This reaction can be represented as

Here Y^– is the incoming nuclophile or and attacking species and x^– is the leaving group.

Example:
Hydrolysis of alkyl halides by aqueous KOH.
CH₃Br  CH₃OH + Br^–
Aliphatic nucleophilic substitution reactions take place either by S_N¹ or S_N² mechanism.

Question 6.
Explain Electrophilic Addition Reaction with suitable example.
Answer:
A general electrophilic addition reaction can be represented as below.

Example:
Bromination of alkene to give bromo alkane

Question 7.
What are oxidation and reduction reactions? Give suitable example.
Answer:
Many oxidation and reduction reactions of organic compounds fall into one of the four types of reaction that we already discussed but others do not. Most of the oxidation reaction of organic compounds involves gain of oxygen or loss of hydrogen Reduction involves gain of hydrogen and loss of oxygen.
Example:

IV. Long answer questions (5 Marks):

Question 1.
Explain different types of Fission of a covalent bond.
Answer:
All organic molecules contain covalent bonds which are formed by the mutual sharing of electrons between atoms. These covalent bonds break in two different ways, namely homolytic cleavage (symmetrical splitting) and heterolytic cleavage (unsymmetrical splitting). The cleavage of a bond in the substrate is influenced by the nature of the reagent (attacking agent).

Homolytic Cleavage:
Homolytic cleavage is the process in which a covalent bond breaks symmetrically in such way that each of the bonded atoms retains one electron. It is denoted by a half headed arrow (fish hook arrow). This type of cleavage occurs under high temperature or in the presence of UV light in a compound containing non polar covalent bond formed between atoms of similar electronegativity.

In such molecules, the cleavage of bonds results into free radicals. They are short lived and are highly reactive. The type of reagents that promote holmolytic cleavage in substrate are called as free radical initiators. For example Azobisisobutyronitile (AIBN) and peroxides such as benzoyl peroxide are used as free radical initiators in polymerisation reactions.

As a free radical with an unpaired electron is neutral and unstable, it has a tendency to gain an electron to attain stability. Organic reactions involve homolytic fission of C – C bonds to form alkyl free radicals. The stability of alkyl free radicals is in the following order:
C(CH₃)₃ > CH(CH₃)₂ > CH₂CH₃ > CH₃

Heterolytic Cleavage:
Heterolytic cleavage is the process in which a covalent bond breaks unsymmetrically such that one of the bonded atoms retains the bond pair of electrons. It results in the formation of a cation and an anion. Of the two bonded atoms, the most electronegative atom becomes the anion and the other atom becomes the cation. The cleavage is denoted by a curved arrow pointing towards the more electronegative atom.

For example, in tert-butyl bromide, the C – Br bond is polar as bromine is more electronegative than carbon. The bonding electrons of the C – Br bond are attracted more by bromine than carbon. Hence, the C – Br undergoes heterolytic cleavage to form a tert-butyl cation during hydrolysis.

Let us consider the cleavage in a carbon-hydrogen (C-H) bond of aldehydes or ketones We know that the carbon is more electronegative than hydrogen and hence the heterolytic cleavage of C-H bonds results in the formation of carbanion (carbon bears a negative charge). For example in aldol condensation the OH- ion abstracts a a-hydrogen from the aldehyde, which leads to the formation of the below mentioned carbanion.

Question 2.
Explain the acidic nature of carboxylic acid.
Answer:
When a halogen atom is attached to the carbon which is nearer to the carboxylic acid group, its -I effect withdraws the bonded electrons towards itself and makes the ionisation of H easy. The acidity of various chioro acetic acid is in the following order. The strength of the acid increases with increase in the -J effect of the group attached to the carboxyl group.

Trichioro acetic acid > Dichloro acetic acid > Chloro acetic acid > acetic acid.

Similarly, the following order of acidity in the carboxylic acids is due to the +I effect of alkyl group.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 6 Random Variable and Mathematical Expectation Miscellaneous Problems Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 6 Random Variable and Mathematical Expectation Miscellaneous Problems

Question 1.
The probability function of a random variable X is given by

Evaluate the following probabilities.
(i) P(X ≤ 0)
(ii) P(X ≤ 0)
(iii) P( X ≤ 2) and
(iv) P(0 ≤ X ≤ 10)
Solution:
(i) From the data

(i) P(x ≤ 0) = P( x = -2) + P(x = 0)
= \(\frac { 1 }{4}\) + \(\frac { 1 }{4}\) = \(\frac { 2 }{4}\) = \(\frac { 1 }{2}\)

(ii) P(x < 0) = P(x = -2) = \(\frac { 1 }{4}\)

(iii) P(|x| ≤ 2) = P(-2 ≤ X ≤ 2)
= P(X = -2) + P(X = 0) = \(\frac { 1 }{4}\) + \(\frac { 1 }{4}\)
= \(\frac { 2 }{4}\) = \(\frac { 1 }{2}\)

(iv) p(0 ≤ X ≤ 10) = P (X = 0) + P(X = 10)
= \(\frac { 1 }{4}\) + \(\frac { 1 }{2}\) = \(\frac { 1+2 }{4}\) = \(\frac { 3 }{4}\)

Question 2.
The probability function of a random variable X is given by

(a) Compute: (i) P(1 ≤ X ≤ 2) and (ii) P(X = 3).
(b) Is X a discrete random variable? Justify your answer.
Solution:
W.K.T Probability density Function
f(x) = \(\frac { d[F(x)] }{dx}\)

(ii) P(X = 3) = 0
(b) X is not discrete since f is not a step function.

Question 3.
The p.d.f. of X is defined as
f(x) = \(\left\{\begin{array}{l}
\mathrm{k}, \text { for } 0<x \leq 4 \\
0, \text { otherwise }
\end{array}\right.\)
Solution:
Let X and a random variable if a Probability density function

Question 4.
The probability distribution function of a discrete random variable X is

where k is some constant. Find (a) k and (b) P(X > 2).
Solution:
(a) Let X be the random variable of a probability distribution function
W.K.T Σpi = 1
P(x = 1) + P(x = 3) + P(x = 5) = 1
2k + 3k + 4k = 1
9k – 1 ⇒ k = 1/9

(b) P(x > 1) = P(x = 3) + P(x = 5)
= 3k + 4k = 7k
= 7(1/9) = 7/9

Question 5.
The probability distribution function of a discrete random variable X is
f(x) = \(\left\{\begin{array}{l}
\mathrm{a}+\mathrm{b} x^{2}, 0 \leq x \leq 1 \\
0, \text { otherwise }
\end{array}\right.\)
where a and b are some constants. Find (i) a and b if E(X) = 3/5 (ii) Var(X).
Solution:
Let X be due continuous variable of density function

Question 6.
Prove that if E(X) = 0, then V(X) = E(X²)
Solution:
V(X) = E(X²) – [E(X)]²
= E(X²) – 0 {Given that E(X) = 0}
Var(X) = E(X²)
Hence proved.

Question 7.
What is the expected value of a game that works as follows: I flip a coin and, if tails pay you ₹ 2; if heads pay you ₹ 1. In either case I also pay you ₹ 50.
Solution:
Let x be the remain variable denoting the amount paying for a game of flip coin then x and takes 2 and 1
P(X = 2) = \(\frac { 1 }{2}\) (getting a head)
p(X = 1) = \(\frac { 1 }{2}\) (getting a tail)
Hence the probability of X is

Expected value E(X) = \(\sum_{ x }\)x P(x)
= (2)(\(\frac { 1 }{2}\)) + 1 (\(\frac { 1 }{2}\))
= 1 + \(\frac { 1 }{2}\) = \(\frac { 3 }{2}\)
Since I pay you ₹ 50 in either case
E(X) = 50 × 3/2 = ₹ 75

Question 8.
Prove that, (i) V(aX) = a²V(X) , and (ii) V(X + b) = V(X).
Solution:
LHS = V(ax)
= E(ax)² – [E(ax)]²
= a² E(x²) – [aE(x)]²
= a²E(x²) – a²E(x)]²
= a²E(x²) – E(x)²]
= a²v(x)
= RHS
Hence proved

(ii) LHS = V(x + b)
= E (x + b)² – [E(x + b)]²
= E(x² + 2bx + b²) – [E(x) + b]² –
= E(x²) + 2bE(x) + b² – [E(x)]² + b² + 2bE(x)]
= E(x²) + 2bE(x) + b² -[E(x)]² + b² – 2bE(x)]
= E(x²) – [E(x)]²
= V(x)
= RHS
LHS = RHS Hence proved.

Question 9.
Consider a random variable X with p.d.f.
f(x) = \(\left\{\begin{array}{l}
3 x^{2}, \text { if } 00 \\
0, \text { otherwise }
\end{array}\right.\)
Find the expected life of this piece of equipment.
Solution:
Let X be the random variable

Question 10.
The time to failure in thousands of hours of an important piece of electronic equipment used in a manufactured DVD player has the density function
f(x) = \(\left\{\begin{array}{l}
2 e^{-2 x}, x>0 \\
0, \text { otherwise }
\end{array}\right.\)
Find the expected life of this piece of equipment.
Solution:
Let X be the random variable

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 6 Random Variable and Mathematical Expectation Ex 6.2 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 6 Random Variable and Mathematical Expectation Ex 6.2

Question 1.
Find the expected value for the random variable of an unbiased die
Solution:
When a un based die is thrown , any one of the number 1, 2, 3, 4, 5, 6, can turn up that x denote the random variable taking the values from 1 to 6

Question 2.
Let X be a random variable defining number of students getting A grade. Find the expected value of X from the given table

Solution:
Let X be a random variable taking values 0, 1, 2, 3,
Expected value E(x) = Σp₁x₁
= (0.2 × 0) + (0.1 × 1) + (0.4 × 2) + (0.3 × 3)
= 0 + 0.1 + 0.8 + 0.9
∴ E(x) = 0.18

Question 3.
The following table is describing about the probability mass function of the random variable X

Find the standard deviation of x.
Solution:
Let x be the random variable taking the values 3, 4, 5
E(x) = Σpixi
= (0.1 × 3) + (0.1 × 4) + (0.2 × 5)
0.3 + 0.4 + 1.0
E(x) = 1.7
E(x²) = Σpixi²
= (0.1 × 3²)+ (0.1 × 4²) + (0.2 × 5²)
= (0.1 × 9) + (0.1 × 16) + (0.2 × 25)
E(x²) = 7.5
Var(x) = E(x²) – (E(x)]²
= 7.5 – (1.7)²
= 7.5 – 2.89
Var(x) = 4.61
Standard deviation(S.D) = \(\sqrt { var (x)}\)
= \(\sqrt { 4.61}\)
σ = 2.15

Question 4.
Let X be a continuous random variable with probability density function
f_x (x) = \(\left\{\begin{array}{l}
2 x, 0 \leq x \leq 1 \\
0, \text { otherwise }
\end{array}\right.\)
Find the expected value of X.
Solution:
Let x be a continuous random variable. In the probability density function, Expected

Question 5.
Let X be a continuous random variable with probability density function
f_x (x) = \(\left\{\begin{array}{l}
2 x, 0 \leq x \leq 1 \\
0, \text { otherwise }
\end{array}\right.\)
Find the mean and variance of X.
Solution:
Let x be a continuous random variable. In the probability density function,

Question 6.
In an investment, a man can make a profit I of ₹ 5,000 with a probability of 0.62 or a loss of ₹ 8,000 with a probability of 0.38 . Find the expected gain.
Solution:

Let x be the random variable of getting gain in an Investment
E(x) be the random variable of getting gain in an Investment
E(x) = ΣPixi
= (0.62 × 5000) + [0.38 × (-8000)]
= 3100 – 3040
E(x) = 60
∴ Expected gain = ₹ 60

Question 7.
What are the properties of mathematical expectation?
Properties of Mathematical expectation
Solution:
i. E(a) = a, where ‘a’ is a constant.
ii. E(aX) = aE(X)
iii. E(aX + b) = aE(X) + b, where ‘a’ and ‘b’ are constants.
iv. If X ≥ 0, then E(X) ≥ 0
v. V(a) = 0
vi. If X is random variable, then V(aX + b) = a²V(X)

Question 8.
What do you understand by mathematical expectation?
Solution:
The average value of a random Phenomenon is termed as mathematical expectation or expected value.
The expected value is weighted average of the values of a random variable may assume

Question 9.
How do you define variance in terms of Mathematical expectation?
Solution:
The variance of X is defined by
Var(X) = Σ[x – E(X)]² p(x)
If X is discrete random variable with probability mass function p(x).
Var(X) = \(\int_{ -∞ }^{∞}\) [x- E(X)]² f_x (x) dx
If X is continuous random variable with probability density function f_x (x).

Question 10.
Define mathematical expectation in tears of discrete random variable?
Solution:
Let X be a discrete random variable with probability mass function (p.m.f.) p(x). Then, its expected value is defined by
E(X) = \(\sum_{ x }\) x p(x) ……(1)

Question 11.
State the definition of mathematical expectation using continous random variable.
Solution:
If X is a continuous random variable and fix) is the value of its probability density function at x, the expected value of X is
E(X) = \(\int_{ -∞ }^{∞}\) x f(x) dx …….(2)

Question 12.
In a business venture a man can make a profit of ₹ 2,000 with a probability of 0.4 or have a loss of ₹ 1,000 with a probability of 0.6. What is his expected, variance and standard deviation of profit?
Solution:
Let X be the random variable of getting profit in a business

E(x) = Σ_xxp_x(x)
= (0.4 × 2000) +[0.6 × (-1000)]
= 800 – 600
E(X) = 200
∴ Expected value of profit = ₹ 200
E(X²) = Σx² P_x(x)
= [(2000)² × 0.4] + [(-1000)² × 0.6]
= (4000000 × 0.4) + (1000000 × 0.6)
E(X²) = 2200000
Var(X) = E(X²) – [E(X)]²
= 22000000 – (200)²
= 2200000 – 40000
Var(X) = 21,60,000
Variance of his profit = ₹ 21,60,000
Standard deviation(S.D) = \(\sqrt { var (x)}\)
σ = \(\sqrt { 2160000}\)
σ = 1469.69
Standard deviation of his profit is ₹ 1,469.69

Question 13.
The number of miles an automobile tire lasts before it reaches a critical point in tread wear can be represented by a p.d.f.

Find the expected number of miles (in thousands) a tire would last until it reaches the critical tread wear point.
Solution:
We know that,

Question 14.
A person tosses a coin and is to receive ₹ 4 for a head and is to pay ₹ 2 for a tail. Find the expectation and variance of his gains.
Solution:
Let X denote the amount the person receives in a game
Then X takes values 4,-2 and
So P(X = 4) = P (of getting a head)
= \(\frac { 1 }{2}\)
P(X = – 2) = P (of getting a tail)
= \(\frac { 1 }{2}\)
Hence the Probability distribution is

E(x²) = 10
Var(x) = E(x²) – E(x²)
= 10 – (1)²
Var(x) = 9
∴ His expected gain = ₹ 1
His variance of gain = ₹ 9

Question 15.
Let X be a random variable and Y = 2X + 1. What is the variance of Y if variance of X is 5?
Solution:
Var(X) = 5
Var(Y) = var (2x + 1) {∴ v(ax + b) = a²v(x)}
= (2)² var(X)
= 4(5)
Var() = 20

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 9 Locomotion and Movement Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter 9 Locomotion and Movement

11th Bio Zoology Guide Locomotion and Movement Text Book Back Questions and Answers

Part I

Question 1.
Muscles are derived from
a) ectoderm
b) mesoderm
c) endoderm
d) neuro ectoderm
Answer:
b) mesoderm

Question 2.
Muscles are formed by
a) myocytes
b) leucocytes
c) osteocytes
d) lymphocytes
Answer:
a) myocytes

Question 3.
The muscles attached to the bones are called
a) skeletal muscle
b) cardiac muscle
c) involuntary muscle
d) smooth muscles
Answer:
a) skeletal muscle

Question 4.
Skeletal muscles are attached to the bones by
a) tendon
b) ligament
c) pectin
d) fibrin
Answer:
a) tendon

Question 5.
The bundle of muscle fibres is called
a) Myofibrils
b) fascicle
c) sarcomere
d) sarcoplasm
Answer:
b) fascicle

Question 6.
The pigment present in the muscle fibre to store oxygen is
a) myoglobin
b) troponin
c) myosin
d) actin
Answer:
a) myoglobin

Question 7.
The functional unit of a muscle fibre is
a) sarcomere
b) sarcoplasm
c) myosin
d) actin
Answer:
a) sarcomere

Question 8.
The protein present in the thick filament is
a) myosin
b) actin
c) pectin
d) leucin
Answer:
a) myosin

Question 9.
The protein present in the thin filament is
a) myosin
b) actin
c) pectin
d) leucin
Answer:
b) actin

Question 10.
The region between two successive Z-discs is called a
a) sarcomere
b) microtubule
c) myoglobin
d) actin
Answer:
a) sarcomere

Question 11.
Each skeletal muscle is covered by
a) epimysium
b) perimysium
c) endomysium
d) hypomysium
Answer:
a) epimysium

Question 12.
Knee joint is an example of
a) saddle joint
b) hinge joint
c) pivot joint
d) gliding joint
Answer:
b) hinge joint

Question 13.
Name of the joint present between the atlas and axis is
a) synovial joint
b) pivot joint
c) saddle joint
d) hinge joint
Answer:
b) pivot joint

Question 14.
ATPase enzyme needed for muscle contraction is located in
a) actinin
b) troponin
c) myosin
d) actin
Answer:
c) myosin

Question 15.
Synovial fluid is found in
a) Ventricles of the brain
b) Spinal cord
c) immovable joint
d) freely movable joints
Answer:
d) freely movable joints

Question 16.
Inflammation of joints due to accumulation of uric acid crystals is called as
a) Gout
b) myasthenia gravis
c) osteoporosis
d) osteomalacia
Answer:
a) Gout

Question 17.
Acetabulum is located in
a) collar bone
b) hip bone
c) shoulder bone
d) thigh bone
Answer:
b) hip bone

Question 18.
Appendicular skeleton is
a) girdles and their limbs
b) vertebrae
c) skull and vertebral column
d) ribs and sternum
Answer:
a) girdles and their limbs

Question 19.
The type of movement exhibits by the macrophages are
a) flagellar
b) ciliary
c) muscular
d) amoeboid
Answer:
d) amoeboid

Question 20.
The pointed portion of the elbow is
a) acromion process
b) glenoid cavity
c) olecranon process
d) symphysis
Answer:
c) olecranon process

Question 21.
Name the different types of movement
Answer:

• Amoeboid movement
• Ciliary movement
• Flagellar movement
• Muscular movement

Question 22.
Name the filaments present in the Sarcomere.
Answer:
Thick and thin filaments are the two types of filaments present inside the sarcomere.

Question 23.
Name the contractile proteins present in the skeletal muscle.
Answer:

• Myosin – Thick filament
• Actin – Thin filament

Question 24.
When describing a skeletal muscle. What does “Striated mean?
Answer:
Each skeletal muscle fibre has a repeated series of dark and light bands. The dark A-bands and light I-bands give a striated appearance to the muscle.

Question 25.
How does an isotonic contraction takes place?
Answer:
In isotonic contraction, the length of the muscle changes but the tension remains constant.
(eg) lifting dumbbells and weight lifting.

Question 26.
How does an isometric contraction take place?
Answer:
In isotonic contraction, the length of the muscle changes but the tension remains constant. The force produced is unchanged, e.g., lifting dumbbells and weight lifting.

Question 27.
Name the bones of the skull.
Answer:
The cranial bones are 8 in number.

1. Paired parietal
2. Paired temporal
3. frontal
4. Sphenoid
5. Occipital
6. Ethmoid

Question 28.
Which is the only jointless bone in the human body?
Answer:
The jointless bone is the hyoid bone in our throat. The hyoid bone (lingual bone) is a horseshoe.

Question 29.
List the three main parts of the axial skeleton.
Answer:

1. Cranium
2. Hyoid (Lingual)
3. Vertebral column
4. Thoracic cavity.

Question 30.
How is tetany caused?
Answer:
Due to the deficiency of parathyroid hormone the level of calcium decreases in the blood that leads to rapid muscle spasm called tetany.

Question 31.
How does rigor mortis happen?
Answer:
After the death of an individual, the membrane of muscle cells becomes more permeable to calcium ions. This happens due to the partial contraction of skeletal muscles. The contracted muscles are unable to relax. This condition is known as rigor mortis.

Question 32.
What are the different types of rib bones that form the rib cage?
Answer:

• True rib bones (First 7 pairs)
• False rib bones (8,9,10th pairs)
• Floating rib bones (11 and 12th pair)

Question 33.
What are the bones that make the pelvic girdle?
Answer:

• Ilium
• Ischium
• Pubis

Question 34.
List the disorders of the muscular system.
Answer:

• Muscle fatigue
• Atrophy
• Muscle pull
• Muscular dystrophy

Arthritis

• Osteoarthritis
• Rheumatoid arthritis
• Gout

Question 35.
Explain the sliding-filament theory of muscle contraction.
Answer:
Sliding filament theory is an active process. It is proposed by Andrw F. Huxley in 1954 and Rolf Niedergerke.

• Muscle contraction is initiated by a nerve impulse sents by the central nervous system through a motor neuron
• When the nerve impulse reaches neuromuscular junction acetylcholine is released and created action potential.
• This action potential triggers the release of calcium from the sarcoplasmic reticulum
• The released calcium ions bind to troponin on thin filaments.
• The active sites are exposed to the heads of myosin to form a cross bridge. Hence actin and myosin form a protein complex called actomyosin.
• Utilizing the energy released from the hydrolysis of ATP the myosin head rotates until it forms a 90° angle with a long axis of the filament.
• The power stroke begins after the myosin head and hinge region tilt from a 90° angle to a 45° angle.
• The cross-bridge transforms into strong high force bond which allows the myosin head to swells it.
• When the myosin head swells it pulls the attached actin filament towards the centre of the A – band.
• The myosin returns back to its relaxed state and releases ADP and phosphate ions. A Newer ATP molecule binds to the head of myosin and the cross-bridge is broken.
• At the end of each power stroke each myosin head detaches from actin then swivels back and binds to a new actin molecule to start another contraction cycle.
• The power stroke repeats many times and the thin filaments move toward the centre of the sarcomere.
• In this process, there is no change in the lengths of thick or thin filaments.
• The Z – discs attached to the actin filaments are also pulled inwards from both sides causing the shortening of the sarcomere. This process continues.
• When motor impulse stops the calcium ions are purnbed back into the sarcoplasmic reticulum results in the masking of the active sites of the actin filament and the myosin head fails to bind with the actin and causes Z – discs back to their original relaxed position.

Question 36.
What are the Benefits of regular exercise?
Answer:

1. The benefits of regular exercise are:
2. The muscles used in exercise grow larger and stronger.
3. The resting heart rate goes down.
4. More enzymes are synthesized in the muscle fibre.
5. Ligaments and tendons become stronger.
6. Joints become more flexible.
7. Protection from a heart attack.
8. Influences hormonal activity.
9. Improves cognitive functions.
10. Prevents obesity.
11. Promotes confidence, esteem.
12. Aesthetically better with a good physique.
13. Overall well-being with good quality of life.
14. Prevents depression, stress, and anxiety.

Part II.

11th Bio Zoology Guide Locomotion and Movement Additional Important Questions and Answers

I. Choose The Best Options

Question 1.
The pseudopodia of amoeba is formed from
a) Cytoplasm
b) Nucleoplasm
c) Sarcoplasm
d) all the above
Answer:
a) Cytoplasm

Question 2.
Where is ciliary movement taking place?
Answer:
a) Respiratory tract
b) Stomach
c) oesophagus
d) Reproductive tract
Answer:
d) Reproductive tract

Question 3.
Name the movement of spermatozoa
a) amoeboid movement
b) flagellated movement
c) Ciliary movement
d) None of the above
Answer:
b) flagellated movement

Question 4.
Muscles are made up of ………………….
a) Myocytes
b) Lymphocytes
c) adenocytes
d) leucocytes
Answer:
a) Myocytes

Question 5.
The cytoplasm of the muscle fibre is called:
a) Myofibril
b) Sarcomere
c) Sarcoplasm
d) Sarcolemma
Answer:
c) Sarcoplasm

Question 6.
Name the connective tissue which covers the entire muscle?
a) Epimycium
b) Perimycium
c) Endomyciurn
d) Mesornyscium
Answer:
a) Epimycium

Question 7.
Name the membrane which covers each fasiculi
a) Epimycium
b) Perirnycium
c) Endomyciurn
d) Mesomvscium
Answer:
b) Perirnycium

Question 8.
Name the membrane which covers each muscle fibre?
a) Epimycium
b) Perimycium
c) Endomycium
d) Mesomysciurn
Answer:
c) Endomycium

Question 9.
Match and Find the Correct Pair
1. Sarcoplasm – a) Respiratory pigment
2. Myoglobin – b) Glucose giver
3. Glycosome – c) Unit of skeletal muscle
4. Sarcomere – d) cytoplasm

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

Question 10.
Find the correct and wrong statement and arrange the following statement.
1. The contraction of muscle fibres depends on the actin and myosin protein.
2. The thick muscle fibres depends on Myosin.
3. Each meromyosin molecule will have a globular head with a long arm.
4. The head of the meromyosin bears an actin-binding site and an ATP binding site.

Answer:
a) True True False True

Question 11.
Name the protein that regulates muscle contraction.
a) Tropomyosin and actin
b) Troponin and myosin
c) tropomyosin and troponin
d) None of the above
Answer:
c) tropomyosin and troponin

Question 12.
Who has proposed sliding – filaments hypothesis?
a) Andrew F. Huxley and Rolf Nieder gerke
b) Andrew F. Huxley and Nelson
c) Andrew F. Pluxley and Darwin
d) Andrew F. Huxley and Mendal
Answer:
a) Andrew F. Huxley and Rolf Nieder gerke

Question 13.
Which chemical initiates the opening of multiple gated channels in sarcolemma?
a) Epinephrine
b) Norepinephrine
c) acetylcholine
d) erythromycin
Answer:
c) acetylcholine

Question 14.
Find out the wrong pair
a) Fast – oxidative fibres – have high ATP ase activity
b) Slow – oxidative fibres – low rates of ATP ase activity
c) Oxidative fibres – less number of mitochondria
d) Red muscle fibres – oxidative fibres
Answer:
c) Oxidative fibres – less number of mitochondria

Question 15.
The skeletal system is formed from this layer!
a) Ectoderm
b) Mesoderm
c) Endoderm
d) Neuroderm
Answer:
b) Mesoderm

Question 16.
………………………… a number of bones forms the endoskeleton of man?
a) 210
b) 220
c) 206
d) 209
Answer:
c) 206

Question 17.
Hove many bones are there in the axial and appendicular skeleton?
a) 80 and 126
b) 126 and 80
c) 80 and 120
d) 80 and 118
Answer:
a) 80 and 126

Question 18.
How many bones are there in the facial and cranial bones?
a) 14 and 9
b) 14 and 8
c) 14 and 10
d) 14 and 12
Answer:
b) 14 and 8

Question 19.
Name the opening of the temporal bone
a) External auditory meatus
b) Nasal opening
c) Optic opening
d) Mouth
Answer:
a) External auditory meatus

Question 20.
Name the U-shaped single bone present at the base of the buccal cavity.
a) Palantine bone
b) Hyoid bone
c) Ethmoid bone
d) Sphenoid bone
Answer:
b) Hyoid bone

Question 21.
How many bones from the vertebral column?
a) 33
b) 32
c) 30
d) 36
Answer:
a) 33

Question 22.
Match and find the correct pair
1) Cervical vertebrae – a) – 5
2) Thoraic – b)-l
3) Pelvic bone – 0-7
4) Cocyx bone – d) -12

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

Question 23.
In which bone ………….. situated?
a) Cervical vertebra
b) thoracic vertebra
c) Pelvic vertebra
d) all the above
Answer:
d) all the above

Question 24.
Name the first vertebra?
a) Atlas
b) Maleus
c) Incus
d) Stapes
Answer:
a) Atlas

Question 25.
Name the second vertebra?
a) Atlas
b) Axis
c) Maleus
d) Stapes
Answer:
b) Axis

Question 26.
How many are the number of ribs?
a) 14 pair
b) 13 pair
c) 12 pair
d) 15 pair
Answer:
c) 12 pair

Question 27.
Match and find the correct answer
1) ribs – a) – 1, 7
2) True ribs – b) -11,12
3) False ribs – c) – Bicephalic
4) Floating ribs – d) – 8,10

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

Question 28.
How many bones are there appendicular skeleton?
a) 130
b) 140
c) 126
d) 122
Answer:
c) 126

Question 29.
Which forms the appendicular skeleton?
a) Upper and hindlimbs
b) Upper limbs and thoracic bones
c) Hind and vertebral column
d) Hind and cranial bones
Answer:
a) Upper and hindlimbs

Question 30.
Name the bones which joint the axial and appendicular skeleton.
a) Clavicle bone
b) Scapula
c) Acromian process
d) None of the above
Answer:
a) Clavicle bone

Question 31.
Flow many bones are there in the upper arm.
a) 30
b) 32
c) 34
d) 36
Answer:
a) 30

Question 32.
Find the wrong pair.
a) Wrist bone – 8
b) Fore arm bones – 30
c) Facial bone -16
d) Cranial bones – 8
Answer:
c) Facial bone -16

Question 33.
Find the wrong pair
a) Palm bones – 5
b) Phalanges -14
c) Thoracic bone – 12
d) Vertebral column – 33
Answer:
d) Vertebral column – 33

Question 34.
Match and find the correct pair.
1) Cervical vertebra – a) – 12
2) Thoracic vertebra – b) – 1
3) Pelvic vertebra – c) – 7
4) Coccyx – d)-5

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

Question 35.
The oxidative skeletal muscle fibres are termed as
a) Fatty muscle fibres
b) White muscle fibres
c) red muscle fibres
d) yellow muscle
Answer:
c) red muscle fibres

Question 36.
Whether the following statement is correct or wrong find out the correct sequence.
1) Pelvic bone Ilium, Ischium, and pubis
2) Acetabulam cavity is present in the sacrum
3) The head of the thigh bone fits in the acetabulum cavity
4) The pubic bones articulate anteriorly at the pubic symphysis
Sequence:
a) 1 – True, 2 – False, 3 – True, 4 – True
b) 1 – False, 2 – False, 3 – True, 4 – True
c) 1 – False, 2 – True, 3 – True, 4 – True
d) 1 – True, 2 – True, 3 – False, 4 – True
Answer:
a) 1 – True, 2 – False, 3 – True, 4 – True

Question 37.
Which is the prominent bone of the pelvic bone?
a) Ilium
b) Ischium
c) Pubis
d) all the above
Answer:
a) Ilium

Question 38.
What is the number of hind limbs?
a) 32
b) 37
c) 30
d) 34
Answer:
c) 30

Question 39.
Name the longest bone
a) Femur
b) Humerus bone
c) Tibia
d) all the above

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

Question 40.
Match and find the correct pair.
1)Patella – a)-14
2) Tarsus – b) -5
3) Metatarsus – c) – 7 bones
4) Phalanges – d) – kneecap
Answer:
3) Metatarsus – c) – 7 bones

Question 41.
Name the membrane which covers the femur bone.
a) Periosteum
b) Endosteum
c) Osteoclast
d) Osteoblast
Answer:
a) Periosteum

Question 42.
Name the joints seen in the cranial region
a) Fibrous joints
b) Cartilagenous joints
c) Diarthroses joints
d) Synovial joints
Answer:
a) Fibrous joints

Question 43.
The Synovial fluid is seen in joints.
a) Cartilagenous joints
b) Diarthroses joints
c) Fibrous joints
d) all the above
Answer:
b) Diarthroses joints

Question 44.
Name the diseases due to the deficiency of acetylcholine.
a) Myasthenia gravis
b) Tetany
c) Duchene muscular dystrophy
d) Muscle pull
Answer:
a) Myasthenia gravis

Question 45.
Name the disease due to the deficiency of ATP
a) Muscle fatigue
b) Muscle pull
c) Muscular dystrophy
d) Tetany
Answer:
a) Muscle fatigue

Question 46.
A tear in the muscle
a) Muscle fatigue
b) Muscle pull
c) Atrophy
d) Muscular dystrophy
Answer:
b) Muscle pull

Question 47.
Name the arthritis due to aging.
a) Osteoarthritis
b) Rheumatoid arthritis
c) Gout
d) Osteoporosis
Answer:
a) Osteoarthritis

Question 48.
Osteoporosis is due to
a) Calcium
b) Sodium
c) Magnesium
d) Potassium
Answer:
a) Calcium

Question 49.
The deposition of urate crystals on the joints is called as
a) Gout
b) Rheumatoid
c) arthritis
d) Osteoporosis
Answer:
a) Gout

Question 50.
Assertion A: Acetylcholine is secreted in the Neuromuscular junction.
Reason B: If acetylcholine is not secreted there won’t be any multiple gated channels in the sarcolemma.
a) A true B wrong
b) A true B this explains the action of A
c) A wrong B true
d) A wrong B wrong
Answer:
b) A true B this explains the action of A

Question 51.
Assertion A: The upper limbs are attached to the pectoral girdles.
Reason B: The pectoral girdles are very light and allow the mobility of the hand
a) A wrong B wrong
b) A True B does not explains the A
c) A True B explains the functions of A
d) A True B wrong
Answer:
c) A True B explains the functions of A

Question 52.
Assertion A: In the pelvis bone a deep socket is present called acetabulum.
Reason B: The head of the femur bone fits in the acetabulum.
a) A True B explains the functions of A
b) A wrong B explains the functions of A
c) A True B wrong
d) B does not explains the structure of B
Answer:
a) A True B explains the functions of A

Question 53.
Assertion A: The pelvis of female is shallow wide and flexible in nature
Cause B: This helps during pregnancy.
a) A True B explains the functions of A
b) A wrong B explains the functions of A
c) A True B wrong
d) B does not explains the structure of A
Answer:
a) A True B explains the functions of A

Question 54.
Assertion A: The lower arm carries the entire weight of the body and is subjected to exceptional forces when we jump or run.
Reason B: To bear the weight of the body it has 46 bones
a) A True B True
b) A wrong B wrong
c) A True B does not explains the functions of A
d) A True B Wrong
Answer:
c) A True B does not explains the functions of A

Question 55.
Assertion A: The cranium belongs to immovable fixed joints.
Reason B: Structures of the flat skull bones are fibrous joints.
a) A True B Wrong
b) A True B explains the structure of A
c) A True B True
d) B does not explains the structure of A
Answer:
b) A True B explains the structure of A

Question 56.
Assertion A: The decreased synthesis of acetylcholine in the neuromuscular junction, causes myasthenia gravis.
Reason B: This leads to muscle fatigue weakness, paralysis.
a) A and B are True
b) A and B are wrong
c) A True B wrong
d) A wrong B True
Answer:
a) A and B are True

Question 57.
Match and arrange the sequence :


Answer:
a) I – D, II – C, III-A,IV – B

Question 58.
Match and arrange the sequence:


Answer:
b) I – C, II – D, III – B, IV -A

2 marks

II. Very Short answers

Question 1.
What is amoeboid movement?
Answer:
The movement of cells by streaming movements of the cytoplasm forming pseudo-podia is known as amoeboid movement, e.g., macrophages.

Question 2.
What are the types of muscles?
Answer:

• Skeletal muscle
• Visceral muscles
• Cardiac muscles

Question 3.
Name the muscle protein?
Answer:

• Actin
• Myosin

Question 4.
Name the regulatory proteins in the thin filaments.
Answer:

• Tropomyosin
• Troponin

Question 5.
Classify the muscles on the basis of their rate of shortening?
Answer:

• Fast contraction fibre
• Slow contraction fibre

Question 6.
On the basis of ATP formation, how are muscles classified?
Answer:

• Oxidative fibres
• Glycolytic fibres

Question 7.
How are muscles classified on the basis of ATP are activity?
Answer:

• Fast oxidative fibres
• Slow oxidative fibres

Question 8.
What is perimysium?
Answer:
The connective tissue covering around each fascicle is the perimysium.

Question 9.
Differentiate the oxidative fibre from the glycolytic fibre.
Answer:

Question 10.
What is sarcoplasm?
Answer:
The cytoplasm of the muscle fibre is called the sarcoplasm.

Question 11.
What is meant by exo skeleton?
Answer:
It is a rigid hard case present outside the body of animals (eg) Cockroach.

Question 12.
What is endo skeleton?
Answer:
It is found inside the body of vertebrates. It is composed of bones and cartilages, (eg) Man.

Question 13.
What are the two types of endo skeletons?
Answer:

1. Axial skeleton.
2. Appendicular skeleton.

Question 14.
What are Glycosomes?
Answer:
Glycosomes are the granules of stored glycogen that provide glucose during the period of muscle fiber activity.

Question 15.
What is a brainbox?
Answer:
The cranial bones form the hard protective outer covering of the brain and called the brain box.

Question 16.
Name the ear ossicles?
Answer:

• Malleus
• incus
• stapes

Question 17.
Give notes on Jaw bones?
Answer:

• It is composed of the upper jaw which is formed of the maxilla and the lower jaw is formed of the mandible.
• The upper jaw is fused with the cranium and is immovable.
• The lower jaw is connected to the cranium and is movable.

Question 18.
Name the openings of the skull?
Answer:

• The orbits
• Nasal cavity
• Foramen magnum

Question 19.
What is meant by foramen magnum?
Answer:

• It is a large opening found at the posterior base of the skull.
• Through this opening, the medulla oblongata of the brain descends down as the spinal cord.

Question 20.
What are oxidative fibres?
Answer:
The muscle fibres that contain numerous mitochondria and have a high capacity for oxidative phosphorylation are classified as oxidative fibres. They are also called red muscle fibres.

Question 21.
Name the first two bones of the vertebral column.
Answer:

1. Atlas
2. Axis

Question 22.
What are the functions of the vertebral column?
Answer:

• It protects the spinal cord.
• Supports the head
• Serves as the point of attachment for the ribs and musculature of the back.

Question 23.
Give short notes on sternum?
Answer:

• The sternum is a flat bone on the mid ventral line of j the thorax.
• It provides space for the attachment of the thoracic ribs and abdominal muscles.

Question 24.
What is a hydrostatic skeleton?
Answer:
The skeleton found in soft-bodied invertebrates is called a hydrostatic skeleton. It is a fluid-filled cavity encircled by muscles, e.g., the earthworm.

Question 25.
What are true ribs?
Answer:
The first seven pairs of ribs are called true ribs. Dorsaily they are attached to the thoracic vertebrae and ventrally connected to the sternum.

Question 26.
What are false ribs?
Answer:
The 8th, 9th, and 10th pairs of ribs do not articulate directly with the sternum but joined with the seventh rib.

Question 27.
What is the sternum?
Answer:
The sternum is a flat bone on the midventral line of the thorax. It provides space for the attachment of the thoracic ribs and abdominal muscles.

Question 28.
What is meant by appendicular skeleton?
Answer:
The bones of the upper and lower limbs along with their girdles constitute the appendicular skeleton. It is composed by 126 bones.

Question 29.
White the 3 segments of lower limb.
Answer:

1. The thigh
2. the leg or the shank and
3. the foot.

Question 30.
What is meant by acromian process?
Answer:
The scapula has a slightly elevated ridge called the spine which projects as flat expanded process called the acromion.

Question 31.
What is meant by glenoid cavity?
Answer:
Below the acromian is a depression called the glenoid cavity which articulates with the head of the humerus to form the shoulder joint.

Question 32.
What is meant by olecranon process?
Answer:
The radius and ultra bones present in the fore arm that form the pointed portion of the elbow called olecranon process.

Question 33.
What is meant by carpal tunnel?
Answer:

• There are 8 bones in the wrist arranged in two rows of four each.
• The anterior surface of the wrist has tunnel like appearance. This tunnel is termed as carpal tunnel.

Question 34.
Name the bones which forms the coxal bones.
Answer:

• Ilium
• Ischium
• Pubis

Question 35.
What is meant by pubic symphysis?
Answer:
Ventrally the two halves of the pelvic girdle meet and form the pubic symphysis containing fibrous cartilage.

Question 36.
Where calcium ion binds with the muscle fibre? Name the molecules which binds with calcium?
Answer:

• The calcium released from sarcoplasma binds with the thin fibre of the muscle.
• The released calcium binds to troponin a thin filaments.

III. Fill Up The Blanks With Suitable Options

1. Scapula – Acromian process
……………. – Bones of upper arm
2. First 7 pair of rib bones – True ribs
11 and 12th pair of ribs – …………….
3. Cervical vertebrae – 7
……………. – Lumbar bones
4. Skull bones – 22
……………. – Skull bones
5. Thick fibres – Myosin
……………. – Thin fibres
6. Amoeboid movement – Macrophage cells
……………. – Sperm cells
Answer:

1. Olecronan process
2. Floating ribs
3. 5
4. 8
5. Actin
6. Flagellated movement

3 marks

IV. Short answers

Question 1.
Give short notes on skeletal muscle and their covering membranes.
Answer:

• Each muscle is made up of bundles of muscle fibres called fascicle. Each muscle fibre contains rod like structures called myofibrils.
• The connective tissue covering the muscle is the epimysium.
• The covering around each fascicle is the perimysium.
• The muscle fibre is surrounded by endomysium.

Question 2.
Give the structure of a skeletel muscle fibre.
Answer:

• Each muscle fibre is thin and elongated.
• Most of them taper at one or both ends.
• Muscle fibres are surrounded by sarcolemma the cytoplasm of the muscle fibre is called the sarcoplasm.
• It contains glycosomes myoglobin and sarcoplasmic reticulum.
• Myoglobin is a red coloured respiratory pigment and glycosomes are reserved glycogen.
• Muscle fibres contain muscle protein actin and myosin.

Question 3.
Give notes on slow oxidative fibres.
Answer:

• These fibres have low rates of myosin ATP hydrolysis but have the ability to make large amounts of ATP.
• This type of fibres seen in long distance swimmers and long distance runners.

Question 4.
Give notes on fast – oxidative fibres.
Answer:

• These fibres have high myosin ATP ase activity and can make large amounts of ATP.
• They are suited for rapid action.

Question 5.
Give notes on fast glycolytic fibres.
Answer:

• These fibres have myosin ATP ase activity but cannot make as much ATP as oxidative fibres because their source of ATP is glycolysis.
• These fibres are best suited for rapid intense actions such as short sprint at maximum speed.

Question 6.
Name the facial bones.
Answer:
There are 14 facial bones.

1. Pair of maxilla
2. Pair of Zygomatic
3. Pair of Palantine
4. Pair of lacrimal
5.  Pair of Nasal
6. Mandible or lower jaw
7. Vomer

Question 7.
Give notes on fibrous joints.
Answer:

• They are immovable fixed joints in which no movement between the bones is possible.
• Sutures of the flat skull bones are fibrous joints.

Question 8.
Give notes on cartilaginous joints.
Answer:
They are slightly movable joints in which the joint surface are separated by a cartilage and slight movement is only possible.

Question 9.
Give notes on synovial joints.
Answer:
They are freely movable joints the articulating bones are separated by a cavity which is filled with synovial fluid.

Question 10.
Give notes on myasthenia gravis.
Answer:

• It is an auto immune disorder affecting the action of acetylcholine at neuro muscular junction leading to fatique.
• Weakening and paralysis of skeletal muscles.
• Acetylcholine receptors on the sarcolemma are blocked by antibodies leading to weakness of muscles.
• When the disease progresses it can make chewing swallowing talking and even breathing difficult.

Question 11.
Give notes on muscle fatique.
Answer:

• It is the inability of a muscle to contract after repeated muscle contraction.
• This is due to lack of ATP and accumulation of lactic acid by anaerobic break down of glucose.

Question 12.
Give notes on Atrophy of muscles.
Answer:

• A decrease in the activity of muscles results in the atrophy of muscles.
• There is a reduction in the size of the muscle and makes the muscle to become weak which occurs with lack of usage as in chronic bed ridden patients.

Question 13.
What is meant by muscle pull?
Answer:

• Muscle pull is actually a muscle tear.
  Atraumatic pulling of the fibres produces a tear known as sprain.
• This can occur due to sudden stretching of muscle beyond the point of elasticity.
• Back pain is a common problem caused by muscle pull due to improper posture with static sitting for long hours.

Question 14.
What is meant by muscular dystrophy?
Answer:

• The group of diseases collectively called the muscular dystrophy are associated with the progressive degeneration of skeletel muscle fibres weakening the muscles and leading to death from lung or heart failure.
• (eg) Duchene muscular dystrophy.

Question 15.
What is meant by skeletel muscle glycogen analysis?
Answer:

• This is used to measure an athlete’s muscle glycogen.
• Muscle glycogen provides the main source of energy during anaerobic exercise.
• A single glycogen molecule may contain 5000 glucose molecules.

Question 16.
Give notes on osteoporosis?
Answer:

• It occurs due to deficiency of vitamin D and hormonal imbalance.
• It causes rickets in children and osteomalasia in adult females.
• The bones become soft and fragile.
• It can be minimized with adequate calcium intake vitamin D intake and regular physical activities.

Question 17.
What is carpal tunnel syndrome?
Answer:

• The narrow passage bounded by bones and ligaments in the wrist get narrowed and pinches the median nerve.
• This syndrome is mostly seen among the clerks, software professional and people who constantly play or text in mobile phones.

5 Marks

V. Give Detailed Answers 

Question 1.
Describe about the different types of movements with examples.
Answer:
Types of Movements :

1. Amoeboid movements
2. Ciliary movements
3. Flagellar movements
4. Muscular movements

1. Amoeboid movements:
Cells such as macrophages exhibit amoeboid movement for engulfing pathogens by pseudopodia formed by the streaming movement of the cytoplasm.

2. Ciliary movements :
This type of movement occurs in the respiratory and genital passages.

3. Flagellar movement:
This type of movement occurs in the cells which are having flagella or whiplike motile organels. (eg) Sperm cells.

4. Muscular movement:
The movement of hands legs jaws are caused by the contraction and relaxation of the muscle.

Question 2.
Describe the structure of sarcomere.
Answer:

• The unit of the skeletal muscle is sarcomere A sarcomere is the region of a myofibril between two successive z – discs.
• It contains an ‘A’ band with a half I band which are perfectly aligned with one another.
• This type of arrangement gives the cell a striated appearance.
• Each dark band has a lighter region in its middle called the M – zone.
• Each H – zone is bisected vertically by a dark line called the M – line.
• The I bands have a darker mid line area called the z – disc.

• Inside the sarcomere two types of filaments are present namely the thick filaments and thin filaments.
• The thick filaments extend the entire length of the A band, the thin filaments extend across the I band and partly into the A – band.
• The invagination of the sarcolemma forms transverse (T- tubules) tubules and they penetrate into the junction between the A and I bands.

Question 3.
Describe the structure of muscle protein.
Answer:
Contraction of the muscle depends on the presence of contractile proteins such as actin and myosin.
Myosin fibre:

• The thick filaments are composed of the protein myosin.
• Each myosin molecule is made up of monomer called meromyosin.
• The meromyosin have a globular head with a j short arm and a tail.
• The short arm have heavy meromyosin and the tail portion have the light meromyosin.
• The head bears an actin – binding site and an ATP binding site
• It also contains ATP ase enzyme that split ATP to generate energy for the contraction of muscle.

Actin filament:

• Actin has polypeptide subunits called globular actin or G – actin and filamentous form F – actin.
• Each thin filament is made of two F – actins helically wound to each other.
• Each F – actin is a polymer of monomeric G – actins, It also contains a binding site for myosin.
• The thin filament contain several regulatory protein like tropomyosin, troponin, which help in regulating the contraction of muscles along with actin and myosin.

Thick filament:
Each thick filament consists of many myosin molecules whose heads produce at opposite ends of the filament Portion of a thick filament

Thin filament:
A thin filament consists of two strands of actin subunits twisted into a helix plus two types of regulatory proteins (troponin and tropomyosin) Portion of a thin filament.

Question 4.
Give the schematic representation of muscle contraction.
Answer:

Question 5.
Give the four important features of skeletal muscles.
Answer:

1. Excitability :
   Based on the chemical and electrical excitation the muscles contracts.
2. Contractility:
   It is the ability of the muscle which gives movement to the attached organs.
3. Conductivity:
   The excitation at one part of the muscle is connected to the other part of the muscle.
4. Elasticity :
   The ability of the muscle to returns to its original position after the extension of the muscles.

Question 6.
Explain the bones that form the skull?
Answer:
The skull is composed of two sets of bones – cranial and facial bones. It consists of 22 bones of which 8 are cranial bones and 14 are facial, bones. The cranial bones form the hard protective outer covering of the brain and called the brain box. The capacity of the cranium is 1500 cm3.

These bones are joined by sutures which are immovable. They are paired parietal, paired temporal and individual bones such as the frontal, sphenoid, occipital and ethmoid. The large hole in the temporal bone is the external auditory meatus. In the facial bones maxilla, zygomatic, palatine, lacrimal, nasal are paired bones whereas mandible or lower jaw and vomer are unpaired bones. They form the front part of the skull.

A single U-shaped hyoid bone is present at the base of the buccal cavity. It is the only bone without any joint. Each middle ear contains three tiny bones- malleus, incus, and stapes collectively are called ear ossicles. The upper jaw is formed of the maxilla and the lower jaw is formed of the mandible.

The upper jaw is fused with the cranium and is immovable. The lower jaw is connected to the cranium by muscles and is movable. The most prominent openings in the skull are the orbits and the nasal cavity. The foramen magnum is a large opening found at the posterior base of the skull. Through this opening, the medulla oblongata of the brain descends down as the spinal cord.

Question 7.
Give an account of vertebral column.
Answer:

• It consists of 33 serially arranged vertebrae which are interconnected by a cartilage known as inter vertebral disc.
• The vertebral column extends from the base of the skull to the pelvis and forms the main framework of the trunk.

It has five major regions, they are

1. Cervical – 7
2. Thoracic vertebrae -12
3. Lumbar vertebrae – 5
4. Sacrum – 5 sacral vertebrae found in the infant which are fused to form one bone in the adult.
5. Coccyx – 1 – 4 Coccy geal vertebrae found in the infant which are fused to form one bone in the adult.

Question 8.
Give an account of the ribcage.
Answer:

• There are 12 pairs of ribs.
• Each rib bone is connected dorsally to the vertebral column and ventrally to the sternum.
• It has two articulation surfaces on its dorsal end called bicephalic.
• The first 7 pairs of ribs are called true ribsorvertebro – sternal ribs.
• Dorsally they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilages.
• The 8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but joined with the cartilaginous part of the seventh rib.
• These are called false ribs or vertebro – chondral ribs.
• The last 11th and 12th pairs of ribs are not connected ventrally.

• They are called as floating ribs or vertebral ribs.
• Thoracic vertebrae ribs and sternum form the rib cage.

Question 9.
Give an account of the pectoral girdle?
Answer:

• The upper limbs are attached to the pectoral girdles.
• These are very light and allow the upper limbs a degree of mobility not seen any where else in the body.
• The girdle is formed of two halves.
• Each pectoral girdle consists of a clavicle or collar bone and a scapula.
• The scapula is a large triangular bone situated in the dorsal surface of the ribcage between the second and seventh ribs.
• It has a elevated expanded process called the acromion.

• The clavicle articulates this process.
• Below the acromion is a depression called the glenoid cavity which articulates with the head of the humerus to form the shoulder joint.
• Each clavicle is a long slender bone with two curvatures which lie horizontally and connect the axial skeleton with the appendicular skeleton.

Question 10.
Describe the structure of the upper limb.
Answer:

• The upper limb consists of 30 separate bones and is specialized for mobility.
• The region between the shoulder and elbow is the humerus.
• The head of humerus articulates with the glenoid cavity of the scapula and forms the shoulder joint.
• The distel end of humerus articulates with the two fore arm bones the radius and ulna
• Olecranon process is situated at the upper end of the ulna which forms the pointed portion of the elbow.
• The hand consists of carpals metacarpals and phalanges.
• Carpals the wrist bones 8 in number are arranged in two rows of four each and form a tunnel termed as carpal tunnel.
• Meta carpals the palm bones are 5 in number and phalanges the digit bones are 14 in number.

Question 11.
Give an account of pelvic girdle.
Answer:

• The pelvic girdle is a heavy structure specialised for weight-bearing.
• It is composed of two hib bones called coxal bones that secure the lower limbs to the axial skeleton.
• Together with the sacrum and coccyx the hib bones form the basin like bonypelvis.
• Each coxal bone consists of three fused bones ilium, ischium, and pubis.
• At the point of fusion of these three bones forms a deep hemispherical socket called the acetabulum present on the lateral surface of the pelvis.
• It receives the head of the femur at hip joint and helps in the articulation of the femur.
• Ventrally the two halves of the pelvic girdle meet and form the pubic symphysis containing fibrous cartilage.
• The ilium is the superior flaring portion of the hip bone. Each ilium forms a secure joint with the sacrum posteriorly.
• The ischium is a curved bar of bone. The ‘V’ shaped pubic bones articulate anteriorly at the pubic symphysis.
• The pelvis of male is deep and narrow with larger heavier bones and the female is shallow wide and flexible in nature and this helps during pregnancy which is influenced by female hormones.

Question 12.
Give an account of the lower limb.
Answer:

• The lower limb consists of 30 bones which carries the entire weight of the erect body and is subjected to exceptional forces when we jump or run.
• The bones of the lower limbs are thicker and stronger than the upper limbs.
• Each lower limb consists of the thigh, the leg or the shank and the foot.
• The femur is the strongest and longest bone of the body.
• The head of femur articulates with the acetabulum of the pelvis to form the hip joint.
• The tibia and fibula form the skeleton of the shank.
• A thick triangular patella forms the knee cap which protects the knee joint arteriorly and improves the leverages of thigh muscles acting across the knee.
• The foot includes the bones of ankle the tarsus (7) the metatarsus (5) and the phalanges or toe ebones. (14)
• The foot supports our body weight and acts as a lever to propel the body forward while walking and running.
• The phalanges of the foot are smaller than those of the fingers.

Question 13.
Give an account of a structure of a typical long bone.
Answer:

• The typical long bone has a diaphysis, epiphyses and membranes.
• A tubular diaphysis or shaft forms the long axis of the bone and has a central medullary cavity.
• The epiphyses are the bone ends.
• Compact bone forms the exterior of epiphyses and their interior contains spongy bone with red marrow.
• The region where the diaphysis and epiphysis meet is called metaphysis.
• The external surface of the entire bone except the joint surface is covered by a double-layered membrane called the periosteum.
• The outer fibrous layer is dense irregular connective tissue.
• The inner osteogenic layer consists of osteoblasts cell. ( bone-forming cells) and osteoclasts cells (E bone – destroying cells)
• There are primitive stem cells osteogenic cells that give rise to the osteoblasts.
• The periosteum is richly supplied with nerve fibres lymphatic vessels and blood vessels.
• Internal bone surfaces are covered with a delicate connective tissue membrane called the endosteum It also contains osteoblasts and osteoclasts cells.
• Between the epiphysis and diaphysis growthplate or epiphyseal plate is present.

Question 14.
Write a short note on Rib cage?
Answer:
There are 12 pairs of ribs. Each rib is a thin flat bone connected dorsally to the vertebral column and ventrally to the sternum. It has two articulation surfaces on its dorsal end, hence called bicephalic.

The first seven pairs of ribs are called ‘true ribs or vertebro-stemal ribs. Dorsally they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilages.

The 8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but joined with the cartilaginous (hyaline cartilage) part of the seventh rib. These are called ‘false ribs’ or vertebro-chondral ribs.

The last 11th and 12th pairs of ribs are not connected ventrally. Therefore, they are called as ‘floating ribs’ or vertebral ribs. Thoracic vertebrae, ribs and sternum together form the ribcage. Rib cage protects the lungs, heart, liver and also plays a role in breathing.

Question 15.
Tabulate the differentiate of joints man
Answer:

Question 16.
Draw the diagram of different types of fracture and arrange them.
Answer:

Question 17.
Bones of the skeletal system. Table: 1 Bones of skeletal system
Answer:

Notes:

1. The strongest muscle in the human: Massetter in cheeks
2. The smallest muscle in the human: Middle ear in stapedius
3. Well moving muscle: Tongue
4. The largest muscle in the human: Buttock in Glutens Maximus
5. The longest muscle in the human : Hip to knee (sartorius)
6. Total number of bones is adults = 206

Question 18.
Explain the basic categories of exercise and physical activity?
Answer:
Exercise and physical activity fall into four basic categories. Endurance, strength, balance, and flexibility. Endurance or aerobic activities increase the breathing and heart rate. They keep the circulatory system healthy and improve overall fitness.

Strength exercises make the muscles stronger. They help to stay independent and cany out everyday activities such as climbing stairs and carrying bags.

Balance exercises help to prevent falls which is a common problem in older adults. Many strengthening exercises also improve balance.

Flexibility exercises help to stretch body muscles for more freedom of joint movements.

Tamilnadu State Board New Syllabus Samacheer Kalvi 12th Business Maths Guide Pdf Chapter 6 Random Variable and Mathematical Expectation Ex 6.1 Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 12th Business Maths Solutions Chapter 6 Random Variable and Mathematical Expectation Ex 6.1

Question 1.
Construct cumulative distribution function for the given probability distribution.

Solution:
F(0) = P(x ≤ 0) = p(0) = 0.3
F(1) = P(x ≤ 1) = p(0) + p(1)
= 0.3 + 0.2 = 0.5
F(2) = P(x ≤ 2) = P(0) + P(1) + P(2)
= 0.3 + 0.2 + 0.4 = 0.9
F(3) = P(x ≤ 3) = P(0) + P(2) + P(3) + P(4)
= 0.3 + 0.2 + 0.4 + 0.1 = 1

Question 2.
Let X be a discrete random variable with the following p.m.f

Find and plot the c.d.f. of X.
Solution:
F(3) = P(x ≤ 3) = P(3) = 0.3
F(5) = P(x ≤ 5) = P(x = 3) + (x = 5)
= 0.3 + 0.2 = 0.5
F(8) = P(x ≤ 8) = P(3) + P(5) + P(8)
= 0.3 + 0.2 + 0.3
= 0.8
F(10) = P(x ≤ 10)
= P(3) + P(5) + P(8) + P(10)
= 0.3 + 0.2 + 0.3 + 0.2
= 1

Question 3.
The discrete random variable X has the following probability function.

where k is a constant. Show that k = \(\frac { 1 }{18}\)
Solution:
From the data
P(x = 2) = kx
= 2k
P(x = 4) = kx
= 4k
P(x = 6) = kx
= 6k
P(x = 8) = k(x – 2)
= k(8 – 2) = 6k
Since P(X = x) is a probability mass function
\(\sum_{x=2}^{8}\) P(X = x) = 1
\(\sum_{i=2}^{∞}\) P(xi) = 1
(i.e) P(x = 2) + P(x = 4) + P(x = 6) + P(x = 8) = 1
2k + 4k + 6k + 6k = 1
18k = 1
∴ k = \(\frac { 1 }{18}\)

Question 4.
The discrete random variable X has the probability function

Solution:
From the data
P(x = 1) = k
p(x = 2) = 2k
p(x = 3) = 3k
P(x = 4) = 4k
Since P(X = x) is a probability Mass function
\(\sum_{x=1}^{4}\) P(X = x) = 1
\(\sum_{i=1}^{∞}\) P(x_i) = 1
p(x = 1) + P(x = 2) + P(x = 3) + P(x = 4) = 1
P(x = 1) + P(x = = 2) + P(x = 3) + P(x = 4) = 1
k + 2k + 3k + 4k = 1
10k = 1
k = \(\frac { 1 }{10}\)
∴ k = 0.1

Question 5.
Two coins are tossed simultaneously. Getting a head is termed as success. Find the t probability distribution of the number of successes.
Solution:
Let X is the random variable which counts the Number of Heads when the coins are tossed the outcomes are stated below

Question 6.
The discrete random variable X has the probability function.

(i) Find k
(ii) Evaluate p( x < 6), p(x ≥ 6)and p(0 < x < 5) (iii) If P(X ≤ x) > 1, 2 then find the minimum value of x.
Solution:
(i) Since the condition of Probability Mass function
\(\sum_{i=2}^{∞}\) P(x_i) = 1
\(\sum_{i=0}^{7}\) P(x_i) = 1
P(x = 0) + P(x = 1) + P(x = 2) + P(x = 3) + P(x = 4) + P P(x = 6) + p(x = 7) = 1
0 + k + 2k + 2k + 3k + k² + 2k² + 7k² + k = 1
10k² + 9k – 1 = 0
10k² + 10k – k – 1 = 0
10k(k + 1) -1(k + 1) = 0
(k + 1)(10k – 1) = 0
k + 1 = 0; 10k – 1 = 0
k = -1 10k = 1
k = \(\frac { 1 }{10}\)
k = -1 is not possible

(ii) P(x < 6)
P(x < 6) = P(x = 0) + P(x = 1) + P(x = 2)+ P(x = 3) + p(x = 4) + P(x = 5)
= 0 + k + 2k +2k + 3k + k²
= 8k + k²

P(x ≥ 6) = P(x = 6) + p(x = 7)
= 2k² + 7k² + k
= 9k² + k

P(0 < x < 5)
= P(x = 1) + P(x = 2) + p(x = 3) + P(x = 4)
= k + 2k + 2k + 3k
= 8k = 8(\(\frac { 1 }{10}\))
∴ P(0 < x < 5) = \(\frac { 8 }{10}\)

(iii) We want the minimum value of x for which P(X ≥ x) > \(\frac { 1 }{2}\)
Now P(X ≤ 0) = 0 < \(\frac { 1 }{2}\)
P(X ≤ 1) = P(x = 0) + P(X = 1) = 0 + k = k
\(\frac { 1 }{10}\) < \(\frac { 1 }{2}\)
P( X ≤ 2) = P(X = 0) + P(X = 1) + P(X = 2)
= 0 + k + 2k = 3k
\(\frac { 3 }{10}\) \(\frac { 1 }{2}\)
P(X ≤ 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 2) + P(X = 3)
= 0 + k + 2k + 2k = 5k
= \(\frac { 5 }{10}\) = \(\frac { 1 }{2}\)
P(X ≤ 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 2) + P(X = 3) + P(X = 4)
= 0 + k + 2k + 2k + 3k = 8k
= \(\frac { 8 }{10}\) > \(\frac { 1 }{2}\)
This Shows that the minimum value of X for which P(X ≤ x) > \(\frac { 1 }{2}\) is 4

Question 7.
The distribution of a continuous random variable X in range (-3, 3) is given by p.d.f.

Verify that the area under the curve is unity.
Solution:
Since(-3, 3) in the range of given p.d.f
Area under the curve A = \(\int_{-∞}^{∞}\) f(x)dx = \(\int_{-3}^{3}\) f(x)dx

Hence the Area under the curve is unity

Question 8.
A continuous random variable X has the following distribution function:

Find (i) k and (ii) the probability density function.
Solution:
(i) Here F(3) – F(1) = 1
K(3 – 1)⁴ – O = 1
K(2)⁴ = 1
K(16) = 1
k = \(\frac { 1 }{16}\)

(ii) The Probability density function
f(x) = \(\frac { d(F(x)) }{dx}\) = \(\left\{\begin{array}{l}
4 k(x-1)^{3}, 1<x \leq 3 \\
0 \text { else where }
\end{array}\right.\)

Question 9.
The length of time (in minutes) that a certain person speaks on the telephone is found to be random phenomenon, with a probability function specified by the probability density function f(x) as

(a) Find the value of A that makes f (x) a p.d.f.
(b) What is the probability that the number of minutes that person will talk over the phone is (i) more than 10 minutes, (ii) less than 5 minutes and (iii) between 5 and 10 minutes.
Solution:
(a) Since f(x) is a probability density Function

b (i) more than 10 minutes

Question 10.
Suppose that the time in minutes that a person has to wait at a certain station for a train is found to be a random phenomenon with a probability function specified by the distribution function

(a) Is the distribution function continuous? If so, give its probability density function?
(b) What is the probability that a person will have to wait (i) more than 3 minutes, (ii) less than 3 minutes and (iii) between 1 and 3 minutes?
Solution:
(i) Yes, the distribution function is continuous on [0, 4]
The probability density function

(b) The probability that a person will have to wait
(i) more than 3 minutes

(iii) between 1 and 3 minutes

Question 11.
Define random variable.
Solution:
A random variable (r.v.) is a real valued function defined on a sample space S and taking values in (-∞, ∞) or whose possible values are numerical outcomes of a random experiment.

Question 12.
Explain What are the types of random variable.
Solution:
Random variables are classified into two types namely discrete and continuous random variables these are important for practical applications in the field of Mathematics and Statistics.

Question 13.
Define dicrete random Variable
Solution:
A variable which can assume finite number of possible values or an infinite sequence of countable real numbers is called a discrete random variable.

Question 14.
What do you understand by continuous random variable?
Solution:
A random variable X which can take on any value (integral as well as fraction) in the interval is called continuous random variable.

Question 15.
Describe what is meant by a random variable
Solution:
If S is a sample space with a probability measure and x is a real valued function defined over the elements of S then x is called a random variable A random variable is also called a change variable.

Question 16.
Distinguish between discrete and continuous random variable
Solution:

Question 17.
Explain the distribution function of random variable
Solution:
The discrete cumulative distribution function or distribution function of a real valued discrete random variable X takes the countable number of points x₁, x₂, …. with corresponding probabilities p(x₁), p(x₂),… and then the cumulative distribution function is defined by
F_x(x) = P(X ≤ x), for all x ∈ R
i.e. F_x (x) = \(\sum_{x \leq x}\) p(x_i)

Question 18.
Explain the terms (i) probability Mass function (ii) probability density function and (iii) probability
Solution:
(i) If X is a discrete random variable with distinct values x₁, x₂, …. x_n, …, then the function, denoted by P_x(x) and defined by

This is defined to be the probability mass function or discrete probability function of X.

(ii) The probability that a random variable X takes a value in the interval [t₁, t₂] (open or closed) is given by the integral of a function called the probability density function f_x(x):
P(t₁ ≤ X ≤ t₂) = \(\int_{t_{1}}^{t_{2}}\) f_x(x)dx.

(iii)The probability distribution of a random variable X is defined only when we have the various values oft the various values of the random variable e.g. x₁, x₂ …… x_n togather with respective probabilities p₁, p₂, p₃ …… p₄ satisfying
\(\sum_{i=1}^{n}\) Pi = 1

Question 19.
What are the properties of (i) discrete random variable and (ii) Continuous random variable
Solution:
(i) The probability mass function p(x) must satisfy the following conditions
(i) p(x_i) ≥ 0 ∀ i,
(ii) \(\sum_{i=1}^{∞}\) p(x_i) = 1

(ii) The probability density functions/)(x) or simply ; by/(x) must satisfy the following conditions.
(i) f(x) ≥ 0 ∀ x and
(ii) \(\int_{-∞}^{∞}\) f(x) dx = 1

Question 20.
State the Properties of distribution function.
Solution:
The function F_x(x) or simply F(x) has the following properties.
(i) 0 ≤ F(x) ≤ 1, -∞ < x < ∞
(ii) F(-∞) = \(\lim _{x \rightarrow-\infty}\) F(x) = 0 and F(+∞) = \(\lim _{x \rightarrow ∞}\) F(x) = 1.
(iii) F(.) is a monotone, non-decreasing function; ; that is, F(a) < F(b) for a < b.
(iv)F(.) is continuous from the right; that is, \(\lim _{h \rightarrow 0}\) F(x + h) = F(x).
(v) F(x) = \(\frac { d }{dx}\) F(x) = f(x) ≥ 0;
(vi) F'(x) = \(\frac { d }{dx}\) F(x) = f(x) ⇒ dF(x) = f(x)dx
dF(x) is known as probability differential of X.
(vii) P(a ≤ x ≤ b) = \(\int_{a}^{b}\) f(x)dx = \(\int_{-∞}^{b}\) f(x)dx – \(\int_{-∞}^{a}\) f(x)dx
= P(X ≤ b) – P(X ≤ a)
= F(b) – F(a)

Tamilnadu State Board New Syllabus Samacheer Kalvi 11th Bio Zoology Guide Pdf Chapter 8 Excretion Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 11th Bio Zoology Guide Chapter 8 Excretion

11th Bio Zoology Guide Excretion Text Book Back Questions and Answers

Part – I

Question 1.
Arrange the following structures in the order that a drop of water entering the nephron would encounter them.
a) Afferent arteriole
b) Bowman’s Capsule
c) Collecting duct
d) Distal tubule
e) Glomerulus
f) Loop of Henle
g) Proximal tubule
h) Renal Pelvis
Answer:
(a), (e), (b), (g), (f), (d), (c), (h)

Question 2.
Name the three filtration barriers that solutes must come across as they move from plasma to the lumen of Bowman’s capsule. What components of the blood are usually excluded by these layers.
Answer:
The three filtration barriers that solutes must come across as they move from plasma to the lumen of Bowman’s capsule are,

1. Glomerular capillary endothelium
2. Basal lamina or basement membrane
3. Epithelium of Bowman’s capsule.
4. Blood corpuscles and plasma protein are excluded by these layers.

Question 3.
What forces promote glomerular filtration? What forces oppose them? What is meant by net filtration pressure?
Answer:

• Glomerulus hydrostatic pressure
• Glomerulus pressure
• Opposing pressure: Colloidal osmotic pressure, Capsular hydrostatic pressure
• Net filtration pressure = Glomerular hydrostatic pressure – (Colloidal osmotic pressure + capsular hydrostatic pressure.

Question 4.
Identify the following structures and explain their significance in renal physiology?
Answer:
a) Juxtaglomerular apparatus It is a specialized tissue in the afferent arteriole of the nephron that consists of macula densa and granular cells.

• Action: The macula densa cells sense distal tubular flow and aspect afferent arteriole diameter.
• Actions of Glandular cells: When there is a fall in glomerular blood flow it can activate Juxta glomerulus cells to release renin from the liver which converts angiotensinogen to angiotensin I.
• Angiotensin converting enzyme converts angiotensin I to angiotensin II.
• It stimulates Na+ reabsorption in the proximal convoluted tubule by vasoconstriction of the blood vessel and increases the glomerular blood pressure.

b) Podocytes:

• The visceral layer of Bowman’s capsule is made of epithelial cells called podocytes.
• The podocytes and the foot processes and the basement membrane of glomerulus act as a filtering membrane.
• Podocytes act in glomerulus filtration.

c) Sphincters in the bladder:

• The sphincters of the bladder regulate urination.
• When the bladder is full the stretching of the urinary bladder stimulates the CNS through the sensory neurons of the parasympathetic nervous system and brings about contraction of the bladder.
• Somatic motor neurons induce the sphincters to close.
• Smooth muscles contract results in the opening of the internal sphincters and relaxing the external sphincter.
• The sphincter opens and the urine is expelled out.

Question 5.
In which segment of the nephron most of the re-absorption of substances takes place?
Answer:
In the proximal convoluted tubule.

Question 6.
When a molecule or ion is reabsorbed from the lumen of the nephron, Where does it go?
Answer:
When a molecule or ion is reabsorbed from the lumen of the nephron, it goes to the bloodstream through an efferent arteriole which carries blood away from the glomerulus. If a solute is filtered and not reabsorbed from the tubule, it goes along with urine.

Question 7.
Which segment is the site of secretion and regulated reabsorption of ions and pH homeostasis?
Answer:

• 1. Distal tubule; 2. Collecting duct
• In the renal tubules H⁺ and NH⁴ are secreted and liberated into the tubules and excreted through
  urine thus maintaining acid base balance.
• For each H⁺ ions from the liberated filtrate one Na⁺ is reabsorbed in the tubules.
• The secreted HCO₃, PO₃ and NH₃ combines to form carbonic acid and phosphoric acids.
• Thus the H⁺ are maintained and their reabsorption is prevented.

Question 8.
What solute is normally present in the body to estimate GFR in humans?
Answer:

• The glomerulus filtrate consists of water glucose amino acids creatinine protein salts and urea.
• These solutes decide the glomerular filtration rate.

Question 9.
Which part of the autonomic nervous system is involved in the micturition process?
Answer:
Parasympathetic nervous system.

Question 10.
If the afferent arteriole of the nephron constricts, what happens to the GFR in that nephron? If the efferent arteriole constricts what happens to the GFR in that nephron? Assume that no autoregulation takes place.
Answer:

• Blood enters the glomerulus faster with greater force through the afferent arteriole and leaves the glomerulus through the efferent arterioles much slower.
• Because afferent arteriole is wider than efferent arteriole.
• The constriction of this does not affect the rate of filtration.

Question 11.
The concentration of urine depends upon which part of the nephron.
Answer:
a) Bowman’s capsule
b) Length of Henle’s loop
c) PCT
d) network of capillaries arising from the glomerulus.
Answer:
b) Length of Henle’s loop

Question 12.
If Henle’s loop were absent from mammalian nephron, which one of the following is to be expected?
a) There will be no urine formation
b) There will be hardly any change in the quality and quantity of urine formed.
c) The urine will be more concentrated
d) The urine will be more dilute
Answer:
d) The urine will be more dilute

Question 13.
What will happen if the stretch receptors of the urinary bladder wall are totally removed?
a) Micturition will continue
b) Urine will continue to collect normally in the bladder
c) There will be micturition
d) Urine will not collect in the bladder
Answer:
a) Micturition will continue

Question 14.
The end product of the Ornithine cycle is
a) Carbon dioxide
b) Uric acid
c) Urea
d) Ammonia
Answer:
c) Urea

Question 15.
Identify the wrong match.

Answer:
b) DCT – Absorption of glucose

Question 16.
Podocytes are the cells present on the
a) Outer wall of Bowman’s capsule
b) Inner wall of Bowman’s capsule
c) Neck of the nephron
d) Wall glomerular capillaries
Answer:
b) Inner wall of Bowman’s capsule

Question 17.
Glomerular filtrate contains
a) Blood without blood cells and proteins
b) Plasma without sugar
c) Blood with proteins but without cells
d) Blood without urea
Answer:
c) Blood with proteins but without cells

Question 18.
Kidney stones are produced due to the deposition of uric acid and Silicates
b) Minerals
c) Calcium Carbonate
d) Calcium oxalate
Answer:
d) Calcium oxalate

Question 19.
Animal requiring the minimum amount of water to produce urine is
a) Ureotelic
b) Ammonotelic
c) Uricotelic
d) Chemotelic
Answer:
c) Uricotelic

Question 20.
Aldosterone acts at the distal convoluted tubule and collecting duct resulting in the absorption of water through
a) Aquaporins
b) Spectrins
c) GLUT
d) Chloride channels
Answer:
a) Aquaporins

Question 21.
The hormone which helps in the reabsorption of water in kidney tubules is
a) Cholecystokinin
b) Angiotensin Il
c) Antidiuretic hormone
d) Pancreozymin
Answer:
c) Antidiuretic hormone

Question 22.
Malpighian tubules remove excretory products from
a) Mouth
b) Oesophagus
c) Haemolymph
d) Alimentary canal
Answer:
c) Haemolymph

Question 23.
Identify the biological term excretion, glomerulus, urinary bladder, glomerular filtrate, ureters, urine, Bowman’s capsule, urinary system, reabsorption, micturition, osmosis, proteins.
Answer:

• A liquid which gathers in the bladder – Urine
• Produced when blood is filtered in a Bowman’s capsule – Glomerular filtrate
• The temporary storage of urine – Urinary bladder
• A ball of intertwined capillaries – Glomerulus
• Removal of unwanted substances from the body – Excretion
• Each contains a glomerulus – Bowman’s Capsule
• Carry urine from the kidneys to the bladder – Ureter
• The scientific term for urination – Micturition
• Regulation of water and dissolved substances in the blood and tissue fluid – Osmoregulation
• Consists of the kidneys ureters and bladder Excretory system
• Removal of useful substances from glomerular filtrate reabsorption
• What solute the do blood contain that is not present in the glomerular filtrate? – Plasma Protein

Question 24.
With regards to toxicity and the need for dilution in water how different are ureotelic and ureocotelic excretions? Give examples of animals that use these types of excretions?
Answer:

• The type of nitrogenous end product (Urea or Uric acid or ammonia) of an animal excretion depends upon the habitat of the animal.
• For the Excretion of Ammonia, more water is needed.
• Animals that excrete most of their nitrogen in the form of ammonia are called ammonites.
• Fishes Amphibians. Uric acid can be eliminated with a minimum loss of water and is called Uricoteles.
• Reptiles, birds insects, landrails. Mammals and terrestrial amphibians excrete urea and are called ureoteles.
  Nitrogenous

Question 25.
Differentiate protonephridia from metanephridia.
Answer:

Question 26.
What is the nitrogenous waste produced by amphibian larvae and by adult animals?
Answer:
The adult amphibian’s excretory product is urea. The larval form of amphibian’s excretory product is ammonia.

Question 27.
How is urea formed in the human body?
Answer:
Urine formation involves three main processes namely Glomerular Alteration, tubular reabsorption and tubular secretion.

I. Glomerular filtration:

• Blood enters the kidney from the renal artery into the glomerulus.
• Blood is composed of water colloidal proteins, sugars and nitrogenous end product.
• The filteration is started in the glomerulus. The fluid that leaves the glomerular capillaries and enters the Bowman’s capsule is called the glomerular filtrate. It formed 170-180 litre within 24 hours.
• Glomerular membrane has large surface area. Blood enters the glomerulus faster with greater force through the afferent arteriole and leaves the glomerulus through the efferent arterioles much slower.
• This is because afferent arteriole is wider than efferent arteriole and the glomerular hydrostatic pressure is around 55 mm Hg.
• Molecules larger than 5mm are barred from entering the tubule.

The two opposing forces are contributed by the plasma proteins in the capillaries.

1. Colloidal osmotic pressure – 30 mm Hg
2. Hydrostatic pressure -15 mm Hg

Both pressures combine. 30 mm Hg + 15mm Hg = 45mm Hg

• The net filtration pressure of 10mm Hg is responsible for the renal filtration.
• Net filtration pressure – Glomerular
• Hydrostatic Pressure – Colloidal Osmotic pressure + Capsular hydrostatic pressure.

Net filteration pressure = 55 mm Hg – (30mm Hg +15mm Hg) = 10mm Hg

II. Tubular reabsorption:

• The volume of filtrate formed per day is around 170 – 180l.
• Urine released is around 1.51 per day. 99% of the glomerular filtrate is reabsorbed by the renal tubules.

Reabsorption in proximal convoluted tubule:

• Glucose lactate amino acids Na in the filtrate are reabsorbed in the PCT.
• Sodium is reabsorbed by active transport through a sodium-potassium pump in the PCT.
• Small amounts of urea and uric acid are reabsorbed.

Reabsorption in Henle Loop:

• Descending limb of Henle’s loop is permeable to water due to the presence of aqua porlns but not permeable to salts.
• Water is lost in the descending limb. Hence Na and Cl get concentrated in the filtrate.
• Ascending limb of Henle’s loop is impermeable to water but permeable to Na⁺, Cl^– andK⁺.

Distal Convoluted Tubule:

• It recovers water and secretes potassium into tubule.
• Na⁺, Cl^-, and water remain in the DCT.
• Reabsorption of HCO₃ takes place to regulate the blood pH.
• Collecting the tubule is permeable to water potassium ions are actively transported into the tubule and Na⁺ to produce concentrated urine.

Tubular Secretion:

• Once it enters the collecting duct water is absorbed and concentrated hypertonic urine is formed.
• For every H secreted into the tubular filtrate, a Na⁺ is absorbed by the tubular cell.
• The H⁺ secreted combines with HCO⁺₃, HPO^–_3, and NH⁺ and gets fixed as H2CO₃, H2PO_3, and NH4⁺.
• Since H⁺ gets fixed in the fluid reabsorption of H⁺is prevented.

Question 28.
Differentiate cortical from medullary nephrons.
Answer:
In the renal tubules proximal convoluted tubule and distal convoluted tubule are situated in the cortical region of the kidney and the loop of Henle is in the medullary region.

Question 29.
What vessels carry blood to the kidneys? Is this blood arterial or venous?
Answer:
Renal artery right and left artery. The blood is arterial.

Question 30.
Which vessels drain filtered blood from the kidneys?
Answer:
Renal vein. The filtered blood is taken from the kidney to inferior vena cava through renal vein.

Question 31.
What is tubular secretion? Name the substances secreted through the renal tubules?
Answer:

• In the distal convoluted tubule the urine becomes hypotonic.
• It contains urea and salts pass from peri tubular blood in to the cells of DCT.
• For every H⁺ secreted a Na⁺ is absorbed by the tubular cell.
  The H⁺ secreted combines HCO₃, HPO₃ and NH₃ and becomes carbonic acid phosphoric acid and ammonium.
• Since H⁺ gets fixed in the fluid reabsorption of H⁺ is prevented.

Question 32.
How are the kidneys involved in controlling blood volume? How is the volume of blood in the body related to arterial pressure?
Answer:

• When the volume of blood decreases the flow pressure, decreases.
• This can be sensed by hypothalamus and osmo receptors are stimulated and anti diuretic hormone is secreted from the neuro hypophysis.
• The aquaporins in the proximal convoluted tubules and collecting tubule reabsorb water. Hence the blood volume increases and the blood pressure increases.

Question 33.
Name the three main hormones that are involved in the regulation of the renal function?
Answer:

• Renin
• Angio Tensin I
• AngioTensin II

Question 34.
What is the function of anti diuretic hormone? Where is it produced and What stimuli increases or decreases its secretion?
Answer:

• ADH which is also called as vasopressin or Anti diuretic hormone is secreted from neuro hypophysis.
• Fluid loss or if blood pressure increases the osmoreceptors of hypothalamus is stimulated and hence neuro hypophysis is stimulated and secretes ADH.
• When the fluid level and pressure is maintained due to the negative feed back mechanism ADH secretion stops.

Question 35.
What is the effect of aldosterone on kidneys and where is it produced?
Answer:

• Due to the stimulation of Angiotensin II the adrenal cortex secretes aldosterone. That causes reabsorption of Na⁺, K⁺ excretion and absorption of water from distal convoluted tubule and collecting tubule.
• This mechanism is known as Renin – Angio tensin Aldosterone system.

Question 36.
Explain the heart’s role in secreting a hormone that regulates renal function? What hormone is this?
Answer:

• Excessive stretch of cardiac atrial cells cause an increase in blood flow to the atria of the heart and release Atrial Natriuretic Peptide or factor (ANF) travels to the kidney where H increases Na+ excretion and increases the blood flow to the glomerulus,
• Acting on the afferent glomerular arterioles as a vasodilator or an efferent arterioles as a vasoconstrictor.
• The first identical natri uretic hormone is atrial natriuretic horome of heart.

Part – II.

11th Bio Zoology Guide Excretion Additional Important Questions and Answers

I. Choose The Correct Answer.

Question 1.
Name the organ that regulates the acid base and water regulation?
a) Kidney
b) Liver
c) Skin
d) Lungs
Answer:
a) Kidney

Question 2.
Whether the following statements are true or false find the correct sequence. Find the correct sequence.
I) According to the environmental changes organism change their osmotic concentration and are called osmo confirmers.
II) Osmo regulators maintain their internal osmotic concentration irrespective of their external osmotic environment.
III) The Euryhaline animals are able to tolerate only narrow fluctuations in the salt concentration?
IV) The steno haline animals can tolerate wide fluctuations in the salt concentration.
Series:
a) I – False, II – True, III – False, IV – True
b) I – True, II – True, III – False, IV- False
c) I – False, II – True, III – False, IV – True
d) I – False, II – False, III – True, IV – True
Answer:
b) I – True, II – True, III – False, IV- False

Question 3.
Name the toxic formed due to the degeneration of amino acid.
a) Urea
b) Uric Acid
c) Ammonia
d) Carbonic Acid
Answer:
c) Ammonia

Question 4.
Find out the odd one out.
a) Ammonoteles – Aquatic Amphibians
b) Urico teles – Birds
c) Ureoteles – Land amphibians
d) Ureoteles – Earthworm (When it is in water)
Answer:
d) Ureoteles – Earthworm (When it is in water)

Question 5.
What is the functional unit of kidney?
a) Nephron
b) Neuron
c) Synapsis
d) Glomerulus
Answer:
a) Nephron

Question 6.
What type of Urine is formed in organism with long Henle’s loop?
a) Isotonic
b) less concentrated
c) Concentrated
d) None of the above
Answer:
c) Concentrated

Question 7.
In the marine organism the kidney with glomerulus produce ………………. type of concentrated urine.
a) Concentrated than body fluid
b) Equal to the concentration of body
c) Less than the concentration of body fluids
d) None of the above
Answer:
b) Equal to the concentration of body

Question 8.
The average weight of human kidney,
a) 100-120g
b)150-200g
c) 120-170g
d) 120-150g
Answer:
c) 120-170g

Question 9.
What is the outer covering of the kidney?
a) Renal fascia perirenal fat capsule pleura
b) Renal fascia perirenal fat capsule peri cardial membrane
c) Renal fascia, Peri renal fat capsule meninges
d) Renal fascia perirenal fat capsule fibrous capsule
Answer:
d) Renal fascia perirenal fat capsule fibrous capsule

Question 10.
What is meant by renal corpuscle?
a) Glomerulus and Bowman’s Capsule
b) Glomerulus and Malpighian capsule
c) Glomerulus and nephron
d) Glomerulus and Henle’s loop
Answer:
d) Glomerulus and Henle’s loop

Question 11.
Regarding renal tubules find the correct sequences.
a) Glomerulus Bowman’s capsule Malpighian capsule uriniferous tubules.
b) Proximal convoluted tubules thick descending loop thin ascending limb distal convoluted tubule.
c) Proximal convoluted tubule, Henle’s loop. Distal convoluted tubule.
d) Proximal convoluted tubule, thin descending limb thick ascending limb distal convoluted tubule.
Answer:
d) Proximal convoluted tubule, thin descending limb thick ascending limb distal convoluted tubule.

Question 12.
Urea is synthesisted through this cycle.
a) Citric cycle
b) Carboxylic Acid cycle
c) Ornithinecycle
d) Arginine cycle
Answer:
c) Ornithinecycle

Question 13.
What is the pressure in the afferent arthery of Glomerulus?
a) 55 mm Hg
b) 50 mm Hg
c) 57 mm Hg
d) 58 mm Hg
Answer:
a) 55 mm Hg

Question 14.
What is the amount of filteration of the glomerulus in 24 hours?
a) 200l
b) 180l
c)190l
d) 170l
Answer:
b) 180l

Question 15.
What should be the size of the molecule that can pass through the tubules from the plasma filtrate?
a) 7 nm
b) 4 nm
c) 5 nm
d) 6 nm
Answer:
c) 5 nm

Question 16.
What is the pressure in glomerulus?
a) 50 mm Hg
b) 60 mm Hg
c) 55 mm Hg
d) 62 mm Hg
Answer:
c) 55 mm Hg

Question 17.
The glomerular pressure encounter ………….. of colloidal osmotic pressure and …………… of hydrostatic pressure.
a) 30mmHg;15mmHg
b) 15mmHg;30mmHg
c) 40 mm Hg; 30 mm Hg
d) 30mmHg;40mmHg
Answer:
a) 30mmHg;15mmHg

Question 18.
What is the net filteration pressure?
a) 55mmHg – (15mmHg + 30mmHg) = 10mm Hg
b) 55 mm Hg – (30 mm Hg +15 mm Hg) =10 mm Hg
c) 55 mm Hg – (35 mm Hg + 5 mm Hg) = 15 mm Hg
d) 55 mm Hg – (5 mm Hg + 35 mm Hg) = 15 mm Hg
Answer:
b) 55 mm Hg – (30 mm Hg + 15 mm Hg) =10 mm Hg

Question 19.
What is the amount of filtrate formed in one minute?
a) 100 ml -125 ml
b) 100 ml -150 ml
c) 120 ml -125 ml
d) 130 ml -140 ml
Answer:
c) 120 ml -125 ml

Question 20.
What is the amount of filtrate formed in a day?
a) 170 ml-200 ml
b) 170 ml-190 ml
c) 170 ml-180 ml
d) 170 ml-185 ml
Answer:
c) 170 ml-180 ml

Question 21.
What is the amount of urine excreted in a day?
a) 1.5l
b) 1l
c) 2l
d) 2.5l
Answer:
a) 1.5l

Question 22.
Which of the following hormones are secreted by the kidney?
a) Renin
b) Gastrin
c) Calcitriol
d) secretin
a) (ii) and (iii)
b) (i) and (iii)
c) (ii) and (iv)
d) (i) and (ii)
Answer:
b) (i) and (iii)

Question 23.
Where is aquaporins present?
a) Proximal convoluted tubule
b) Distal convoluted tubule and ascending limb of Henle
c) The descending limb of Henle and distal convoluted tubule
d) All the above
Answer:
b) Distal convoluted tubule and ascending limb of Henle

Question 24.
Name the hormone that helpsin the reabsorption of water in distal convoluted tubule.
a) Vasopressin
b) Serotonin
c) Oxytocin
d) All the above
Answer:
a) Vasopressin

Question 25.
Where is Renin synthesized in Kidney?
a) Afferent arteriole
b) Efferent arteriole
c) Vasarecta
d) Collecting duct
Answer:
a) Afferent arteriole

Question 26.
Name the hormone that helpsin the conversion of plasma protein angioten- sinogen into angiotensin I
a) Renin
b) Vasopressin
c) ADH
d) STH
Answer:
a) Renin

Question 27.
What is micturition?
a) Excretion of urine from the urinary bladder
b) The formation of urine in the glomerulus
c) Urine formation in distal convoluted tubule
d) the absorption of urine in Bowman’s capsule
Answer:
a) Excretion of urine from the urinary bladder

Question 28.
According to the food that maneats the pH of urine ……………… to ……………. can be altered.
a) pH 4.8-7.5
b) PH 4.9-7.9
c) pH 4.5-8.0
d) pH 4.4 -7.4
Answer:
c) pH 4.5-8.0

Question 29.
What is the reason for the yellow colour of the urine?
a) Urochrome
b) Haemoerythrin
c) Haemocyanin
d) None
Answer:
a) Urochrome

Question 30.
What is the normal pH of urine?
a) pH 6.0
b) pH 5.3
c) pH 6.4
d) pH 5.9
Answer:
a) pH 6.0

Question 31.
What is the amount of CO₂ released from lungs in a day?
a) 20l
b) 19l
c)18l
d)119l
Answer:
c)18l

Question 32.
Confirm
Statement A: The important function of sweat gland is to cool the body.
Statement B: The sweat glands excrete sodi¬um chloride urea and lactic acid.
a) Statement A-True B-True
b) Statement A-True B-False
c) Statement A-FalseB-True
d) Statement A – False B – False
Answer:
a) Statement A-True B-True

Question 33.
Confirmation:
Statement S: When kidney fails suddenly there is more chance of recovery.
Statement T: In the chronic kidney failure there may not be any chance of recovery.
a) Statement S-True T-True
b) Statement S-True T-False
c) Statement S-True T-True
d) Statement S – True T – False
Answer:
c) Statement S-True T-True

Question 34.
Confirmation:
Statement A: The kidney infection leads to inflammation of bladder and kidney
Statement B: Urination with pain, urinary urgency bloodytinged urine.
a) Statement A – True Statement B explain the symptom of A.
b) A – True – The statement B does not explains the statement A
c) A and B are false
d) A False B – True
Answer:
a) Statement A – True Statement B explain the symptom of A.

Question 35.
What is the normal urea level in the blood
a) 17-30mg/100ml
b) 30-35mg/ 100ml
c) 10-15 mg/100 ml
d) 5-10 mg/100 ml
Answer:
a) 17-30mg/100ml

Question 36.
Find the wrong pair.
a) Renal stone – nephrolithiasis
b) Urine – Urochrome
c) Deficiency of ADH – Urine out put decreases
d) Skin- Lactic acid excretion
Answer:
c) Deficiency of ADH – Urine out put decreases

Question 37.
Confirmation:
Statement A: Bright’s disease is due to the infection of streptococcus in children
statement B: There is inflammation of glomerulus.
a) Statement A and Bare false
b) Statement A True B explain the A
c) A True B False
d) A False B – True
Answer:
b) Statement A True B explain the A

Question 38.
Find the wrong pair.
a) Heporin – Anticoagulating factor
b) Glomerulo nephritis – Accumulation of water in the body
c) Primary kidney – Meso nephridia
d) Uremia – Increase in the blood urea level
Answer:
c) Primary kidney – Meso nephridia

Question 39.
How much urine can be stored up in the bladder?
a) 300-600 ml
b) 200-300 ml
c) 400-700 ml
d) 500-800 ml
Answer:
a) 300-600 ml

Question 40.
For how much time urine can be held in the bladder?
a) 6 hours
b) 2 hours
c) 5 hours
d) 3 hours
Answer:
c) 5 hours

Question 41.
The urinary bladder is made up this muscle ……………………….
a) Detrusor muscle
b) Striated muscle
c) Sphincter muscle
d) None of the above
Answer:
a) Detrusor muscle