9th Std Science Solution in English | Lesson.12 Living World of Plants – Plant Physiology

 Lesson 12 Plant Physiology

Plant Physiology Book Back Answer

I. Multiple choice Questions:

1. The tropic movement that helps the climbing vines to find a suitable support is __________

1. phototropism
2. geotropism
3. thigmotropism
4. chemotropism

Ans: thigmotropism

3. The chemical reaction occurs during photosynthesis is _______

1. CO₂ is reduced and water is oxidized
2. water is reduced and CO₂ is oxidized
3. both CO₂ and water are oxidized
4. both CO₂ and water are produced

Ans: CO₂ is reduced and water is oxidized

3. The bending of root of a plant in response to water is called __________

1. Thigmonasty
2. Phototropism
3. Hydrotropism
4. Photonasty

Ans: Hydrotropism

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 ____________.

1. Chemotropism
2. Geotropism
3. Phototropism
4. Thigmotropism

Ans: Phototropism

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

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)

Ans: (ii) and (iii)

6. The non-directional movement of a plant part in response to temperature is called ________

1. Thermotropism
2. Thermonasty
3. Chemotropism
4. Thigmonasty

Ans: Thermonasty

7. Chlorophyll in a leaf is required for __________.

1. photosynthesis
2. tropic movement
3. transpiration
4. nastic movement

Ans: photosynthesis

8. Transpiration takes place through _____________

1. fruit
2. seed
3. flower
4. stomata

Ans: stomata

9. Transpiration is best defined as __________.

1. loss of water by the plant
2. evaporation of water from the aerial surfaces from the plant
3. loss of water in the form of water vapour from the underground parts of the plant body
4. release of water from the plant into the atmosphere

Ans: evaporation of water from the aerial surfaces from the plant

10. A big tree falls in a forest but its roots are still in contact with the soil. The branches of this fallen tree straight up. This happens in response to ___________.

1. water and light
2. water and minerals
3. gravity and water
4. light and gravity

Ans: water and light

II. Fill in the blanks

1. The shoot system grows upward in response to _________

Ans: Phototropism

2. __________ is positively hydrotropic as well as positively geotropic.

Ans: Root

3. The green pigment present in the plant is ________

Ans: Chlorophy II

4. The solar tracking of sunflower in accordance with the path of sun is due to __________

Ans: Phototropism

5. The response of a plant part towards gravity is ________

Ans: geotropism

6. Plants take in carbondioxide for photosynthesis but need __________ for their living.

Ans: oxygen

7. The minerals like nitrogen, potassium and phosphorus, are required in substantial quantity by the plants are called ___________

Ans: Macronutrients

III. Match column A with column B

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

1. The response of plant to the chemical stimulus is called phototropism.

Ans: False

Correct Ans: Chemotropism.

2. Shoot is positively phototropic and negatively geotropic.

Ans: True 

3. When the weather is hot water evaporates lesser which is duet o opening of stomata.

Ans: False

Correct Ans: When the weather is hot water evaporates more which is due to opening of stomata.

4. Photosynthesis produces glucose and carbon dioxide.

Ans: False

Correct Ans:Photosynthesis generates glucose and oxygen.

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

Ans: True 

6. Plants lose water when the stomata on leaves are closed.

Ans: False

Correct Ans: Plants lose water when stomata are open in the leaves.

7. Scientific term used to represent the bending of roots towards water is called geotropism.

Ans: False

Correct Ans: Hydrotropism

8. Joseph Priestley devised an experiment to find out that water alone was the cause of the increase in the weight of the plant.

Ans: False

Correct Ans: It was VanHelmont who thought that water alone was the cause of the increase in weight of the plant.

VII. Short Answer:

1. Give an example for a plant whose leaf shows a mesmerizing movement.

Desmodium gyrans (Indian Telegraph plant)

2. Write the scientific terms used to represent the following:

a) Growing of roots towards the gravity.

positive geotropism and positive hydrotropism – root.

b) Bending of roots towards the water.

Positive phototropism – stem

VII. Answer the following in one or two sentences

1. What is nastic movement?

Some movements in plants not directed towards stimuli is known as Nastic movement.

2. Name the plant part.

a) Which bends in the direction of gravity but away from the light?

root

b) Which bends towards light but away from the force of gravity?

Shoot

3. Differentiate Phototropism from Photonasty

4. Photosynthesis converts energy X into energy Y

a) What are X and Y

X – Solar energy; Y- Chemical energy

b) Green plants are autotrophic in their mode of nutrition, why?

Green plants have green pigment, so can prepare food directly from sunlight using CO2 and H2O as raw material. Almost all the organisms rely on plant for their food – so green plants are autotrophic.

7. Define Transpiration.

The loss of water in the form of water vapour from the aerial parts of the plant body is called Transpiration.

6. Name the cell that surrounds the stoma.

Each stomata is enclosed by guard cells.

VI. Answer briefly.

1. Give the technical terms for the following:

a) Growth dependent movement in plants.

Tropic movements

b) Growth independent movement in plants.

Nastic movements

2. Explain the movement seen in Pneumatophores of Avicennia

• Pneumatophores are specialized roots that are involved in the respiration of plants.
• These types of roots absorb gas through their lenticels. A small hole in both.

3. Fill in the blanks:

Ans:

4. What is chlorophyll?

Chlorophyll – Green pigment in leaves.

5. Name the part of plant which shows positive geotropism. Why?

Root shows positive geotropism based on the unidirectional movement in response to gravity.

6. What is the difference between movement of flower in sunflower plant and closing of the leaves in the Mimosa pudica?

Movement of flower in Sunflower plant

In sunflower plant the stem tip follows the path of the sun from dawn to dusk (east to west) and at night it moves from west to east. It is a growth movement and takes place in response to a stimulus ‘light’. This is an example of tropic movement in response to light and is called phototropism

Closing of the leaves in the Mimosa pudica

In Mimosa pudica the closing of the leaves is a response to touch. It is not a growth movement and occurs independently of the direction of stimulation. This is a bad movement. and is called Thigmonasti.

7. Suppose you have a rose plant growing in a pot, how will you demonstrate transpiration in it?

Tie a plastic bag around the leaves of the rose plant and place it in the sun. A few hours later, we see water pooling inside the plastic bag. This is caused by the loss of water in the form of water vapor, which condenses into water. It is because of transpiration.

8. Mention the differences between stomatal and lenticular 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
• A very small percentage of water is lost by lenticular transpiration of plants.

9. To which directional stimuli do (a) roots respond (b) shoots respond?

(a) Roots respond positively to photolysis and negatively to photolysis.

(b) Shoots respond negatively to geomorphology and positively to photoinhibition.

VII. Answer in detail.

1. Differentiate between tropic and nastic movements

2. How will you differentiate the different types of transpiration?

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 continuous supply of minerals.
4. It regulates the temperature of the plant.

VIII. Higher Order Thinking Skills.

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 of plant B open their petals at night but closes during the day when there is 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 plant A and B.

Photonasty

b) Name one plant each which behaves like the flowers of plant A and B.

• Plant A – Common Dadelion – Taraxacum Officinale
• Plant B – Moonflower – Ipomoea alba

c) Name the phenomenon exhibited by the leaves of plant C.

Nyctinasty

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?

Requirement of light as a factor for photosynthesis.

b) Why was the plant kept in the dark before the experiment?

Destarch the plant before beginning the experiment. After the experiment, if any starch is found in the leaf, it is only starch produced by the leaves during the experiment.

c) How will you prove that starch is present in the leaves?

• The pot plant is kept in bright sunlight for 4 to 6 hours.
• Selected closed leaf is plucked and black paper is removed.
• The leaf is immersed in boiling water for a few minutes, then the chlorophyll is extracted in alcohol.
• Now the leaf is tested with iodine solution for starch.
• The closed part of the leaf does not turn blue-black, whereas the closed part of the leaf turns blue-black.
• The covered part of the leaf that does not receive sunlight is unable to synthesize starch.
• So it doesn’t turn blue-black.
• But the covered part of the leaf which received sunlight was able to synthesize starch, so it turned blue-black.

WORK BOOK

I. Multiple Choice Questions

1. The bending of root of a plant in response to water is called………….

1. thigmonasty
2. phototropism
3. hydrotropism
4. photonasty

Ans: hydrotropism

2. A growing seeding is kept in the dark room. A burning candle is placed near it for a few days. The top part of the seeding bends towards the burning candle. This is an example of …….

1. chemotropism
2. thigmotropism
3. phototropism
4. geotropism

Ans: phototropism

3. The root of the plant is ………….

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)

Ans: (ii) and (iii)

4. The plant part which exhibits negative geotropism is ………….

1. root
2. stem
3. branch
4. leaves

Ans: stem

5. The non-directional movement of a plant part in response to temperature is called …………..

1. thermotropism
2. thermonasty
3. chermotropism
4. thigmonasty

Ans: thermonasty

6. Dandelion flowers open the petals in bright light during the day time but close the petals in dark at night. The response of Dandelion flowers is called ……………

1. geonasty
2. thigmonasty
3. chemonasty
4. photonasty

Ans: photonasty

7. During photosynthesis plants exhale …………

1. carbondioxide
2. oxygen
3. hydrogen
4. helium

Ans: oxygen

8. ChlorophyII in a leaf is required for ………….

1. photosynthesis
2. transpiration
3. tropic movement
4. nastic movement

Ans: photosynthesis

9. A plant is kept in a dark room for about 24 hours before conducting any experiment on
photosynthesis in order to ……….

1. remove chlorophyII from the leaf.
2. remove starch from the leaves.
3. ensure that photosynthesis occurred.
4. to prove transpiration.

Ans: remove starch from the leaves.

10. Transpiration takes place through ……………

1. fruit
2. seed
3. flower
4. stomata

Ans: stomata

II. Fill in the blanks

1. The solar tracking of sunflower in accordance with the path of sun is due to ___________

Ans: heliotropism

2. The response of a plant part towards gravity is __________

Ans: geotropism

3. When the leaves of a sensitive plant are touched with a fnger, they fold up and when light fades at dusk the petals of a Dandelion fower close.  Tese two plants show ____ and_____ movements.

Ans: thigmonastic and photonastic

4. Opening and closing of Moon flower is not a tropism because the movement in this is ______.

Ans: Ny….nasty

5. The raw materials for photosynthesis are _________ and _______

Ans: CO₂ and H₂O

6. When iodine solution is added for testing starch, part of the leaf with _______ turn blue-black colour.

Ans ; starch

7. In leaves, the food is stored in the form of _________.

Ans ; starch

8. Plants may inhale carbon dioxide for photosynthesis but need ___________ for their living.

Ans ; oxygen

9. Plants utilize only _______% of the absorbed water for photosynthesis and the other activities.

Ans ; 1%

10. Plants inhale and exhale continuously through the __________.

Ans ; stomata

III. State whether the following statements are true or false. If false write the correct

1. When the leaves of Mimosa Pudica plant are touched with the finger, they fold up quickly. This is an example of thigmonasty. ( True )

2. The petals of moon flower open up in morning and closes in the evening. This is called photonasty. ( False )

Ans : Open in night and closes in the day. The movement is thermonasty (or) photonasty.

3. Photosynthesis produces glucose and carbondioxide. ( False )

Ans : It produces glucose and oxygen,

4. Photosynthesis is important in releasing oxygen to keep the atmosphere in balance. ( True )

5. Plants lose water when the stomata on leaves are closed. ( False )

Ans : Plant lose water when the stomata on leaves are kept open.

IV Match the following

1. Name the part of plant which shows positive geotropism. Why?

Tendency of roots to grow downwards is known as positively geotropic.

2. What does a Mimosa pudica plant do in response to touch? What is phenomenon known as?

It folds up and droop and this phenomenon is known as thigmonasty or seismonasty.

3. i) What happens to the dandelion flower a) during the day time; b) at night

ii) What is the phenomenon known as?

During the day time the flower unfolds and it closes in the evening or night. This phenomenon is known as photonasty.

4. What is the difference between the movement of flower in sunflower plant and closing of the leaves in the Minosa pudica?

In Sunflower, the flower tracks and moves in response to the direction of sun. This response is known as Heliotropism.

In Mimosa pudica (touch-me-not) plant the leaves fold up and droop. This type of movement is also nown as seismonasty or thigmonasty.

Unlike tropic movement, nastic movements are independent of the stimulus direction and may or may not be growth movement.

5. Complete the following table with the different types of tropism:

6. Mention the difference between Stomatal and lenticular transpiration.

7. Give an example for the movement plant part which is very quick and can be observed easily.

The easily observable and quick movement that can be seen in a plant is the falling of leaf – in Mimosa pudica by thigmonasty.

8. To which directional stimuli do

a) roots respond;

The roots respond to geotropic and hydrotropic stimuli where as

b) shoots respond?

shoots respond to phototropic stimulus.

9. Name the cell that surround the stoma?

The cells that surround the stoma are guard cells.

V. Analog

1. Towards a stimulus : _____________ Away from the stimulus : Negative tropism

Ans : Positive Tropism

2. Hydrotropism : Response towards water Phototropism : ___________

Ans : Response towards light

3. Photosynthesis : ____________ Transpiration : Stomata

Ans : ChlorophyII

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