One Mark Questions Answers

PLANT PHYSIOLOGY

TEXT BOOK EXERCISES

I. Choose the correct answer :

1. The tropic movement that helps the climbing vines to find a suitable support is _{――― .}

(a) Phototropism

(b) Geotropism

(c) Thigmotropism

(d) Chemotropism

[Answer: (c) Thigmotropism]

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]

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] 

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]

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)]

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]

7. Chlorophyll in a leaf is required for _{――― .}

(a) photosynthesis

(b) tropic movement

(c) transpiration

(d) nastic movement

[Answer: (a) photosynthesis]

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 light.

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

3. The green pigment present in the plant is chlorophyll.

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

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

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

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 Chemotropism.

2. Shoot is positively phototropic and negatively geotropic.

Answer: True.

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.

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.