Tamilnadu State Board New Syllabus Samacheer Kalvi 9th Science Guide Pdf Chapter 19 Plant Physiology Text Book Back Questions and Answers, Notes.

Tamilnadu Samacheer Kalvi 9th Science Solutions Chapter 19 Plant Physiology

9th Science Guide Plant Physiology Text Book Back Questions and Answers

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

I. Choose the correct answer :

Question 1.
The tropic movement that helps the climbing vines to find a suitable support is …………….
(a) phototropism
(c) thigmotropism
(b) geotropism
(d) chemotropism
Answer:
(c) thigmotropism

Question 2.
The chemical reaction occurs during photosynthesis is .
(a) CO2 is reduced and water is oxidized
(b) water is reduced and CO2 is oxidized
(c) both CO2 and water are oxidized
(d) both CO2 and water are produced
Answer:
(a) CO2 is reduced and water is oxidized

Question 3.
The bending of root of a plant in response to water is called …………………….
(a) Thigmonasty
(b) Phototropism
(c) Hydrotropism
(d) Photonasty
Answer:
(c) Hydrotropism

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
A growing seedling is kept in the dark room. A burning candle is placed near it for a few days. The tip part of the seedling bends towards the burning candle. This is an example of ……………
(a) Chemotropism
(b) Geotropism
(c) Phototropism
(d) Thigmotropism
Answer:
(c) Phototropism

Question 5.
The root of the plant is …………………
i) positively phototropic but-negatively geotropic
ii) positively geotropic but negatively phototropic
iii) negatively phototropic but positively hydrotropic
iv) negatively hydrotropic but.positively phototropic
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(b) (ii) and (iii)

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
The non-directional movement of a plant part in response to temperature is called………………..
(a) Thermotropism
(b) Thermonasty
(c) Chemotropism
(d) Thigmonasty
Answer:
(b) Thermonasty

Question 7.
Chlorophyllin a leaf is required for …………………
(a) photosynthesis
(b) tropic movement
(c) transpiration
(d) nastic movement
Answer:
(a) photosynthesis

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 8.
Transpiration takes place through ………………..
(a) fruit
(b) seed
(c) flower
(d) stomata
Answer:
(d) stomata

II. Fill in the blanks :

1. The shoot system grows upward in response to ………………..
Answer:
light

2. ………………..is positively hydrotropic as well as positively geotropic.
Answer:
root

3. The green pigment present in the plant is………………..
Answer:
chlorophyll

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

4. The solar tracking of sunflower in accordance with the path of sun is due to …………………
Answer:
phototropism:

5. The response of a plant part towards gravity is ………………..
Answer:
geotropism

6. Plants take in carbon dioxide for photosynthesis but need ……………….. for their living.
Answer:
oxygen

III. Match column A with column B

Column A

Column B

1. Roots growing downwards into soil. Positive phototropism
2. Shoots growing towards the light. Negative geotropism
3. Shoots growing upward. Negative phototropism
4. Roots growing downwards away from light. Positive geotropism

Answer:

Column A Column B
1. Roots growing downwards into soil. Positive geotropism
2. Shoots growing towards the light. Positive phototropism
3. Shoots growing upward. Negative geotropism
4. Roots growing downwards away from light. Negative phototropism

IV. State whether true or false. If false, correct the statement:

1. The response of a part of plant to the chemical stimulus is called phototropism.
Answer:
False.
Correct statement : The response of a plant part to the chemical stimulus is called Itemoiropisin.

2. Shoot is positively phototropic and negatively geotropic.
Answer:
True.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

3. When the weather is hot, water evaporates lesser which is due to opening of stomata.
Answer:
False.
Correct statement: When the weather is hot, water evaporates more but stomata begin to close to reduce evaporation.

4. Photosynthesis produces glucose and carbon dioxide.
Answer:
False.
Correct statement: Photosynthesis produces glucose and oxygen.

5. Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
Answer:
True

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

6. Plants lose water when the stomata on leaves are closed.
Answer:
False.
Correct statement: Plants lose water when the stomata on leaves are open.

V. Answer very briefly :

Question 1.
What is nastic movement?
Answer:
Non-directional response to the stimulus is called Nastic movements.

Question 2.
Name the plant part
a) Which bends in the direction of gravity but away from the light.
b) Which bends towards the light but away from the force of gravity.
Answer:
a) Root system
b) Shoot system.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 3.
Differentiate phototropism from photo nasty.
Answer:
Phototropism:

  1. Movement of a plant part towards the light.
  2. Eg: Shoot of a plant.

Photonasty:

  1. Movement of a plant part is a response to light.
  2. Eg: Moonflower, Taraxacum Officinale.

Question 4.
Photosynthesis converts energy X into energy Y.
a) What are X and Y?
b) Green plants are autotrophic in their mode of nutrition. Why?
Answer:
a) X → light energy,
Y → Chemical energy.
b) Green plants are autotrophic in their mode of nutrition because they prepare then- own food materials through photosynthesis.

Question 5.
Define transpiration.
Answer:
The loss of water in the form of water vapour from the aerial parts of the plant body is called Transpiration.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
Name the cell that surrounds the stoma.
Answer:
Each stomata is surrounded by guard cells.

VI. Answer briefly :

Question 1.
Give the technical terms for the following :
a) Growth dependent movement in plants.
b) Growth independent movement in plants.
Answer:
a) Tropic movements
b) Nastic movements

Question 2.
Explain the movement seen in Pneumatophores of Avicennia.
Answer:

  • Pneumato[hores are specialized roots that can involve in the respiration of plants,
  • This type of roots intakes the gas through its lenticel. a small hole in their both.

Question 3.
Fill in the blanks:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 1
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 2

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
What is chlorophyll?
Answer:
Chlorophyll is a green pigment present in all green plants with is responsible for the absorption of light to provide energy for photosynthesis.

Question 5.
Name the part of plant which shows positive geotropism. Why?
Answer:
Root shows positive geotropism because of the unidirectional movement in response to gravity.

Question 6.
What is the difference between the movement of flowers in the sunflower plant and the closing of the leaves in the Mimosa pudica?
Answer:
Movement of flower in sunflower plant:
In sunflower plant the stem tip follows the path of the sun from dawn to dusk (East to est) and in night it moves from West to East. This is a growth movement and takes place in response to the stimulus ‘light’. It is an example of tropic movement in response to light and is called phototropism.

Closing of the leaves in the Mimosa pudica :
The closing of leaves in Mimosa pudica occurs in response to touch. It is not a growth movement and occurs independently of the direction of stimulus. This is nastic movement . and is called Thigmonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 7.
Suppose you have a rose plant growing in a pot, how will you demonstrate transpiration in it?
Answer:
Tie a plastic bag over leaves of rose plant and place in sunlight. After a few hours, we see water condensing inside the plastic bag. This is due to loss of water in the form of water vapour, which condenses into water. This is due to transpiration.

Question 8.
Mention the differences between stomatal and lenticular transpiration.
Answer:
Stomatal transpiration :

  1. Loss of water from plants through stomata.
  2. 90-95% of transpiration in a plant takes place through stomata only.

Lenticular transpiration :

  1. Loss of water from plants as vapour through the lenticels.
  2. A very small percentage of water is lost by through plants lenticular transpiration.

Question 9.
To which directional stimuli do (a) roots respond (b) shoots respond?
Answer:
(a) Roots respond positively geostrophic and negatively phototrophic.
(b) Shoots respond negatively geostrophic and positively phototrophic.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VII. Answer in detail :

Question 1.
Differentiate between tropic and nastic movements
Answer:
Tropic movements

  1. Unidirectional response to the stimulus.
  2. Growth dependent movements.
  3. More or less permanent and irreversible.
  4. Found in all plants.
  5. Slow action.

Nastic movements :

  1. Non-directional response to the stimulus
  2. Growth independent movements. –
  3. Temporary and reversible.
  4. Found only in a few specialized plants.
  5. Immediate action.

Question 2.
How will you differentiate the different types of transpiration?
Answer:
There are three types of transpiration:
Stomatal transpiration: Loss of water from plants through stomata. It accounts for 90- 95% of the water transpired from leaves.
Cuticular transpiration: Loss of water in plants through the cuticle.
Lenticular transpiration: Loss of water from plants as vapour through the lenticels. The lenticels are tiny openings that protrude from the barks in woody stems and twigs as well as in other plant organs.
But transpiration is necessary for the following reasons.

  1. It creates a pull in leaf and stem.
  2. It creates an absorption force in roots.
  3. It is necessary for a continuous supply of minerals.
  4. It regulates the temperature of the plant.

VIII. Higher Order Thinking Skills:

Question 1.
There are 3 plants A, B and C. The flowers of A open their petals in bright light during the day but closes when it gets dark at night. On the other hand, the flowers f of plant B open their petals at night but closes during the day when there is a bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object.
(a) Name the phenomenon shown by the flowers of plants A and B.
(b) Name one plant each which behaves like the flowers of plant A and B.
(c) Name the phenomenon exhibited by the leaves of plant C.
Answer:
(a) Photonasty
(b) Plant A – Common Dandelion – Taraxacum officinale
Plant B – Moonflower – Ipomoea alba
(c) Nyctinasty

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
Imagine that student A studied the importance of certain factors in photosynthesis.
He took a potted plant and kept it in dark for 24 hours. In the early hours of the next
morning, he covered one of the leaves with dark paper in the centre only. Then he placed the plant in sunlight for a few hours and tested the leaf which was covered
with black paper for starch.
(a) What aspect of photosynthesis was being investigated?
(b) Why was the plant kept in the dark before the experiment?
(c) How will you prove that starch is present in the leaves?
Answer:
(a) Necessity of light as a factor for Photosynthesis.
(b) To make the plant starch-free before starting the experiment. After the experiment, if starch is found in the leaf it will be the starch prepared by leaves during the experiment only.
(c) Presence of starch in the leaves can be proved by doing the starch test.

  • The potted plant is kept in bright sunlight for 4 to 6 hours.
  • The selected covered leaf is plucked and the black paper is removed.
  • The leaf is immersed in boiling water for a few minutes and then in alcohol to remove chlorophyll.
  • The leaf is now tested with iodine solution for the presence of starch.
  • The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue-black colour.
  • The covered part of the leaf which did not receive the sunlight was unable to synthesize starch.
  • Hence it does not turn blue-black colour.
  • But the uncovered part of the leaf which received sunlight was able to synthesize starch and so it turns blue-black in colour.

Intext Activities

ACTIVITY – 1

Take a glass trough and fill it with sand. Keep a flower pot containing water, plugged at the bottom at the centre of the glass trough. Place some soaked pea or bean seeds around the pot in the sand. What do you observe after 6 or 7 days? Record your observation.

Aim : To demonstrate hydrotropism.
Materials required : Glass trough, sand, flower pot, plugged at the bottom, pea or bean seeds and water.

Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 3

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Procedure :

  1. A glass trough is taken and is filled with sand. A flowerpot containing water plugged at the bottom is kept at the centre of the glass trough.
  2. Soaked pea or bean seeds are placed around the pot in the sand. It is observed after 6 or 7 days.

Observation: Observed that radicle has grown towards the pot and moisture instead of growing vertically downward.
Inference: It proves that primary root is positively hydrotropic.
Result: Hydrotropism has been demonstrated by showing positive hydrotropism in roots.

[End of the activity]

ACTIVITY – 2

Take pea seeds soaked in water overnight. Wait for the pea seeds to germinate. Once the seedling has grown put it in a box with an opening for light on one side. After few hours, you can clearly see how the stem has bent and grown towards the light.

Aim : To demonstrate phototropism.
Materials required : Box, water, light and pea seeds.

Procedure:

  1. Take pea seeds soaked in water overnight. Wait for the pea seeds to germinate.
  2. Once the seedling has grown put it in a box with an opening for light on one side.
  3. After few hours, you can clearly see how the stem has bent and grown towards the light.

Observation : Observed that movement of a stem of a plant (pea seeds) towards light moist condition. This is the way a new plant develops from a seed.
Inference : Positive phototropism of a plant has been demonstrated.

[End of the activity]

ACTIVITY – 3

Pluck a variegated leaf from Coleus plant kept in sunlight. De- starch it by keeping in dark room for 24 hours. Draw the picture of this leaf and mark the patches of cholorphyll on the leaf. Immerse the leaf in boiling water followed by alcohol and test it for starch using iodine solution. Record your observation.

Aim : To show that chlorophyll is essential for photosynthesis.
Materials required : Plant with variegated leaves, boiling water, alcohol and iodine solution.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 4

Procedure:
Variegated leaf is plucked from Coleus plant kept in sunlight. It isde-starched by keeping it in dark room for 24 hours. The picture of this leaf is drawn and the patches of cholorphyll on the leaf are marked. After immersing the leaf in boiling water followed by alcohol it is tested for starch with iodine solution.

Observation : The patches of the leaf with chlorophyll turn blue-black. The other portions remain colourless.
Inference: The chlorophyll is essential for photosynthesis.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

ACTIVITY – 4

Place a potted plant in a dark room for about 2 days to de-starch its leaves. Cover one of its leaves with the thin strip of black paper as shown in the picture, make sure that the leaf is covered on both sides. Keep the potted plant in bright sunlight for 4 to 6 hours. Pluck the selected covered leaf and remove the black paper.
Immerse the leaf in boiling water for a few minutes and then in alcohol to remove chlorophyll. Test the leaf now with iodine solution for the presence of starch. The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue-black colour. Why are the changes in colour noted in the covered and uncovered part of the leaf?
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 5

Aim : To show that light is essential for photosynthesis.
Materials required : Covered leaf, boiling water, alcohol and iodine.

Procedure:

  1. A potted plant is placed in a dark room for about 2 days to de-starch its leaves.
  2. One of its leaves is covered with a thin strip of black paper as shown in the picture.
  3. Make sure that the leaf is covered on both sides.
  4. The potted plant is kept in bright sunlight for 4 to 6 hours.
  5. The selected covered leaf is plucked and the black paper is removed.
  6. Th e leaf is immersed in boiling water for a few minutes and then in alcohol to remove chlorophyll.
  7. The leaf is now tested with iodine solution for the presence of starch.

Observation : The covered part of the leaf does not turn blue-black whereas the uncovered part of the leaf turns blue black colour. The covered part of the leaf which did not receive sunlight was unable to synthesize starch.
Inference : The light is essential for photosynthesis.

9th Science Guide Plant Physiology in Animals Additional Important Questions and Answers

I. Choose the correct answer :

Question 1.
The bending of root of a plant in response to water is called …………………..
(a) thigmonasty
(b) phototropism
(c) hydrotropism
(d) photonasty
Answer:
(c) hydrotropism

Question 2.
A growing seedling is kept in the dark room. A burning candle is placed near it for a few days. The top part of the seedling bends towards the burning candle. This is an example of ……………………
(a) chemotropism
(b) thigmotropism
(c) phototropism
(d) geotropism
Answer:
(c) phototropism

Question 3.
The root of the plant is ……………………
(i) positively phototropic but negatively geotropic.
(ii) positively geotropic but negatively phototropic.
(iii) negatively phototropic but positively hydrotropic.
(iv) negatively hydrotropic but positively phototropic.
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(b) (ii) and (iii)

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 4.
The plant part which exhibits negative geotropism is ……………………
(a) root
(b) stem
(c) branch
(d) leaves
Answer:
(b) stem

Question 5.
The non-directional movement of a plant part in response to temperature is called…………………..
(a) thermotropism
(b) thermonasty
(c) chemotropism
(d) thigmonasty
Answer:
(b) thermonasty

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 6.
Sunflowers open the petals in bright light during the day time but close the petals in dark at night. This response of sunflowers is called ……………………
(a) geonasty
(b) thigmonasty
(c) chemonasty
(d) photonasty
Answer:
(d) photonasty

Question 7.
During photosynthesis plants exhale ……………………
(a) Carbon dioxide
(b) oxygen
(c) hydrogen
(d) helium
Answer:
(b) oxygen

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 8.
Chlorophyll in a leaf is required for ……………………
(a) photosynthesis
(b) transpiration
(c) tropic movement
(d) nastic movement
Answer:
(a) photosynthesis

Question 9.
A plant is kept in a dark room for about 24 hours before conducting any experiment on photosynthesis in order to ……………………
(a) remove chlorophyll from the leaf
(b) remove starch from the leaves
(c) ensure that photosynthesis occurred
(d) to prove transpiration
Answer:
(b) remove starch from the leaves

Question 10.
Transpiration takes place through ……………………
(a) fruit
(b) seed
(c) flower
(d) stomata
Answer:
(d) stomata

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 11.
Thigmonasty can be seen in ……………………
(a) Mimosa pudica
(b) Taraxacum officinale
(c) Ipomea alba
(d) Rhizophora
Answer:
(a) Mimosa pudica

Question 12.
The venus flytrap plants are examples for …………………..
(a) chemotropism
(b) thigmonasty
(c) hydrotropism
(d) thigmotropism
Answer:
(b) thigmonasty

Question 13.
………………….. flowers bloom as the temperature increases.
(a) Rose
(b) Jasmine
(c) Lilly
(d) Tulip
Answer:
(d) Tulip

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 14.
Only green plants have the unique capacity to release ………………….. into the atmosphere.
(a) nitrogen
(b) oxygen
(c) carbon dioxide
(d) ozone
Answer:
(b) oxygen

Question 15.
The end product of photosynthesis is ……………………
(a) glucose
(b) sucrose
(c) fructose
(d) none of the above
Answer:
(a) glucose

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

II. Fill in the blanks :

1. The minerals like nitrogen, potassium and phosphorus, are required in substantial quantity by the plants are called …………………..
Answer:
macronutrients

2. The solar tracking of sunflower in accordance with the path of sun is due to ………………………
Answer:
phototropism

3. The response of a plant part towards gravity is ………………………
Answer:
geotropism

4. When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk the petals of a sunflower. These two plants show ……………………..and ……………………..movements.
Answer:
thigmonastic, photonastic

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

5. Opening and closing of Moon flower is not a tropism because the movement in this is……………………..
Answer:
independent of stimulus

6. The raw materials for photosynthesis are …………………….. and ………………………
Answer:
carbon dioxide, water

7. When iodine solution is added for testing starch, part of the leaf with …………………….. turn blue- black colour.
Answer:
starch

8. In leaves, the food is stored in the form of……………………..
Answer:
starch

9. Plants may inhale carbon dioxide for photosynthesis but need ……………………..for their living.
Answer:
oxygen

10. Plants utilize only ……………………..% of the absorbed water for photosynthesis and the other activities.
Answer:
1

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

11 . Plants inhale and exhale continuously through the . ……………………..
Answer:
stamata

12. The bending of shoot towards light is due to the hormone ……………………..
Answer:
auxin

13. Heliotropism is a kind of ……………………..
Answer:
phototropism

14. The ……………………..plant exhibits one of the fastest known nastic movements.
Answer:
venus flytrap

15. Chlorophyll differs from haemoglobin by the presence of its central molecule ……………………..
Answer:
magnesium

16. Plants exchange gases ……………………..continuously through these stomata.
Answer:
CO2 to O2

17. Guard cells help in regulating the ……………………..
Answer:
rate of transpiration

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

III. Analogy :

Question 1.
Towards a stimulus : ……………….:: Away from the stimulus : Negative tropism
Answer:
Positive tropism

Question 2.
Hydrotropism : Response towards water :: Phototropism : …………..
Answer:
Response towards light

Question 3.
Photosynthesis : ……………….. :: Transpiration : Stomata
Answer:
Green leaves

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

IV. State whether the following statements are true or false. If false, write the correct statement :

1. Scientific term used to represent the bending of roots towards water is called geotropism.
Answer:
False.
Correct statement: Scientific term used to represent the bending of roots towards water is called hydrotropism.

2. When the leaves of Mimosa pudica plant are touched with the finger, they fold up quickly.
Answer:
True.
Correct statement: This is an example of thigmonasty.

3. The petals of moon flower open up in morning and closes in the evening. This is called photonasty.
Answer:
False.
Correct statement :The petals of moon flower dost ‘ in the morning and opens up in the evening. This is called photonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

4. Photosynthesis produces glucose and carbon dioxide.
Answer:
False.
Correct statement: Photosynthesis produces glucose and oxygen.

5. Photosynthesis is important in releasing oxygen to keep the atmosphere in balance.
Answer:
True.

6. Plants lose water when the stomata on leaves are closed.
Answer:
False.
Correct statement: Plants will not lose water when the stomata on leaves are closed.

V. Assertion and reason :

Question 1.
Assertion (A) : If the plant part moves in the direction of gravity, it is called positive geotropism.
Reason (R) : Stem shows positive geotropism.
(a) A and R are incorrect
(b) A is incorrect, R is correct
(c) A is correct, R is incorrect
(d) Both A and R are correct
Answer:
(c) A is correct, R is incorrect

Question 2.
Assertion (A) : The loss of excess water from the aerial parts of the plant in the form of water vapour is known as transpiration.
Reason (R) : Stomata of the leaf perform transpiration.
(a) A and R are incorrect
(b) A is incorrect, R is correct
(c) A is correct, R is incorrect
(d) Both A and R are correct
Answer:
(d) Both A and R are correct

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VI. Short answer questions :

Question 1.
Write the scientific terms used to represent the following:
(a) Growing of roots towards the gravity.
(b) Bending of roots towards the water.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 6
Answer:
(a) Positive geotropism
(b) Positive hydrotropism.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
Observe the given picture.
(a) Identify this plant. What type of special movement is shown by this plant?
(b) What are the other movements seen in this plant?
Answer:
(a) Mimosa pudica.
Special movement shown by the plant: Just a casual touch is enough to make the leaves of Mimosa pudica (Touch-me- not plant) fold up and droop. This is described as seismonasty or thigmonasty.
Movements which are not directed towards stimuli but are independent of the stimulus direction are called as nastie movements. They may or may not be growth movement.

(b) The foliage of Mimosa closes during darkness and reopens in the presence of light. Note : The ‘rapid movement of in leaflets in Mimosa is rare in the plant kingdom and is related to changes in turgor pressure.

Question 3.
What is the end product of photosynthesis?
Answer:
The end product of photosynthesis is glucose which is converted into starch and stored in the plant parts.

Question 4.
Name the minute openings seen on the lower surface of the leaf.
Answer:
Stomata are the minute openings seen on the lower surface of the leaf.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 5.
Give the scientific terms for the following:
(a) Growth dependent movement in plants.
(b) Growth independent movement in plants.
Answer:
(a) Tropic movements
(b) Nastie movements.

Question 6.
Study the pictures below and then complete the table by putting a plus (+) if the shoot or root grows towards the stimulus and a minus (-) if it grows away from it.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 7
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 8
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 9

Question 7.
What is the other name for thigmonasty?
Answer:
Seismonasty.

Question 8.
Which flowering plant shows photonasty just opposite to that of Dandelion?
Answer:
Moon flower.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 9.
Give an example for negative hydrotropism.
Answer:
Growth of certain fungal hyphae away from the source of water/moisture.
Note : No clear evidences of negative hydrotropism.

Question 10.
Which gas is evolved during photosynthesis?
Answer:
Oxygen.

Question 11.
Give an example for micronutrients.
Answer:
Zinc.

Question 12.
What does a Mimosapudica plant do in response to touch? What is the phenomenon known as?
Answer:
In response to touch, the leaves of the plant Mimosa pudica fold up and droop. The movement is known as seismonasty or thigmonasty.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 13,
(i) What happens to the dandelion flower
(a) During the daytime?
(b) At night?
(ii) What is the phenomenon known as?
Answer:
(i) (a) The dandelion flower unfolds.
(b) The dandelion flower closes.
(ii) The phenomenon is known as photonasty.

Question 14.
Define photosynthesis.
Answer:
‘Photo’ means Tight’ and ‘synthesis’ means ‘to build’ thus photosynthesis literally means ‘building up with the help of light’. During this process, the light energy is converted into chemical energy. Green plants are autotrophic in their mode of nutrition because they prepare their food materials through a process called photosynthesis.\

Question 15.
Draw the structure of stomata and label the parts.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 10

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 16.
Complete the following table with the different types of tropism:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 11
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 12

Question 17.
Label the diagram with the raw materials and products of photosynthesis.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 13
Answer:
A. Carbon dioxide
B. Water
C. Glucose
D. Oxygen

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 18.
Give an example for the movement of plant part which is very quick and can be observed easily.
Answer:
Just a casual touch is enough to make the leaves of Mimosa pudica fold up and droop. This takes place quickly and can be easily observed.

Question 19.
Name the cell that surrounds the stoma.
Answer:
Guard cells.

Question 20.
Give an example for chemotropism.
Answer:
During fertilization, pollen tube grows down the style in response to the sugars in the style is an example of chemotropism.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 21.
Give the overall equation for photosynthesis.
Answer:
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 14

Question 22.
Guard cells of stomata are green but cannot photosynthesize? Give reason.
Answer:
The enzymes needed for photosynthetic reactions are absent and hence guard cells cannot photosynthesize. _ .

Question 23.
Why do roots of halophytes show negative geotropism.
Answer:
The roots turn 180° upright for respiration.

Question 24.
Why do stems show postive phototropism?
Answer:

  • Stem growing up and towards light is more likely to get sunlight for photosynthesis and display its flowers prominently for pollinators to arrive.
  • It also has better chance of spreading its seeds.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 25.
Mention four factors required for photosynthesis?
Answer:
Chlorophyll, Water, Carbon dioxide and Light.

Question 26.
Why is transpiration called as necessary evil?
Answer:
Water is lost by transpiration but still it is a necessary process since it gives the following advantages to the plant.

  • Creates an absorption force in roots to suck more water form the soil.
  • Regulates the temperature of the plant. Hence transpiration is said to be a necessary evil.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 27.
What are stomata?
Answer:
The leaves have tiny holes, t ailed slomaia, through which the exchange of air takes place. The leaves have tiny, microscopic pores called stomata. Water evaporates through these stomata. Each stomata is surrounded by guard cells. These guard cells help in regulating the rate of transpiration by opening and closing of stomata.

Question 28.
Write the scientific terms used to represent.
Answer:
Leaves fold up and droop in touch-me-not plant Mimosa pudica Ans. Thigmonasty or Seismonasty.
Example: Brunnichia ovata and Mimosa pudica.

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VII. Long answer questions :

Question 1.
Write a note on Transpiration.
Answer:

  • The loss of water in the form of wate r vapour from the aerial parts of the plant body is called as transpiration.
  • The leaves have tiny, microscopic pores called stomata.
  • Water evaporates through these stomata. Each stomata is surrounded by guard cells.
  • These guard cells help in regulating the rate of transpiration by opening and closing of stomata.

Question 2.
Write the types of tropism.
Answer:
Types of Tropism :
Based on the nature of stimuli, tropism can be classifi ed as follows.
Phototropism : Movement of a plant part towards light, e.g. shoot of a plant.
Geotropism : Movement of a plant in response to gravity, e.g. root of a plant.
Hydrotropism : Movement of a plant or part of a plant towards water, e.g root of a plant.
Thigmotropism : Movement of a plant part due to touch, e.g. climbing vines.
Chemotropism : Movement of a part of plant in response to chemicals, e.g growth of a pollen tube in response to sugar present on the stigma.

Tropism is generally termed positive if growth is towards the signal and negative if it is away from the signal. Shoot of a plant moves towards the light, the roots move away. Th us the shoots are positively phototropic.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 15
Usually shoot system of a plant is positively phototropic and negatively geotropic and root system is negatively phototropic and positively geotropic.
Samacheer Kalvi 9th Science Guide Chapter 19 Plant Physiology 16

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

VIII. Higher Order Thinking Skills :

Question 1.
While conducting experiments to study the effects of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X however bends ” away from stimulus A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to factors related with Earth. Keeping these points in mind, answer the following questions:
(a) What could be stimulus A ?
(b) Name the stimulus seen in B.
(c) What could be stimulus-C?
Answer:
(a) Stimulus A – Water
(b) Stimulus B – Gravity
(c) Stimulus C – Light

Samacheer Kalvi 9th Science Guide Chapter 20 Organ Systems in Animals

Question 2.
An organism A which cannot move from one place to another makes a simple food B from the substances C and D available in the environment. This food is made in the presence of green coloured substance E present in organs F in the presence of light energy in a process called G. Some of the simple food B also gets converted into a complex food H for storage purposes. This food gives blue-black colour with iodine solution?
(a) What is (i) organism A (ii) food B and food H?
(b) What are C and D?
(c) Name (i) green coloured substance E and organ F.
(d) What is the process G?
Answer:
(a) (i) Organism A refers to Green plants.
(ii) Food B – Glucose
Food H – Starch

(b) C – Carbon dioxide
D – Water

(c) Green coloured substance E – Chlorophyll
Organ F – Leaves

(d) G – Photosynthesis process.