Plant Physiology Book Back Questions 9th Science Lesson 19

9th Science Lesson 19

19] Plant Physiology

Book Back Questions with Answer and Do You Know Box Content

Do You Know?

Some halophytes produce negatively geotropic roots (eg. Rhizophora). These roots turn 180^o upright for respiration.

The Venus Flytrap (Dionaea muscipula) presents a spectacular example of thigmonasty. It exhibits one of the fastest known nastic movements.

Do the insects also trap solar energy? Tel Aviv University Scientists have found out that Vespa orientalis (Oriental Hornets) have similar capabilities to trap solar energy. They have a yellow patch on its abdomen and an unusual cuticle structure which is a stack of 30 layers thick. The cuticle does not contain chlorophyll but it contains the yellow light sensitive pigment called xanthopterin. This works as a light harvesting molecule transforming light energy into electrical energy.

Choose the best answers:

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

(a) Phototropism

(b) Geotropism

(c) Thigmotropism

(d) Chemotropism

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

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

(a) Thigmonsaty

(b) Phototropism

(c) Hydrotropism

(d) Photonasty

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

5. The root of the plant is ________________

i) Positively phototropic but negatively geotropic

ii) Positively geotropic but negatively phototrophic

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)

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

(a) Thermotropism

(b) Thermonasty

(c) Chemotropism

(d) Thigmonasty

7. Chlorophyll in a leaf is required for _____________

(a) Photosynthesis

(b) Tropic movement

(c) Transpiration

(d) Nastic movement

8. Transpiration takes place through ______________________

(a) Fruit

(b) Seed

(c) Flower

(d) Stomata

Fill in the blanks:

1. The shoot system grows upward in response to ______________.

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

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

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

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

6. Plants take in carbon-dioxide for photosynthesis but need ____________ for their living.

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

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

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

2. Shoot is positively phototropic and negatively geotropic.

3. When the weather is hot, water evaporates lesser which is due to opening of stomata.

4. Photosynthesis produces glucose and carbon dioxide.

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

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

Choose the best answers:

1. Thigmotropism 2. CO2 is reduced and water is oxidized 3. Hydrotropism 4. Phototropism 5. (ii) and (iii) 6. Thermonasty

7. Photosynthesis 8. Stomata

Fill in the blanks:

1. Negative geotropism 2. Root 3. Chlorophyll 4. Auxin(phototropism) 5. Geotropism 6. oxygen

Match column A with 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

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

1.False

Correct answer: The response of a part of plant to the chemical stimulus is called chemotropism

2.True

3.False

Correct answer: When the weather is hot, water evaporates faster which is due to opening of stomata.

4.False

Correct answer: Photosynthesis produces glucose and oxygen

5.True

6.False

Correct answer: Plants lose water when the stomata on leaves are open