Stomata: Opening and Closing

Q.

Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long? Give reasons for your answer.

Q.

___ are pores in the leaf that allow gas exchange in the plant.

Q.

In CAM plants, stomata are:

1. Open during night and close during day.

2. Open during the day and close at night.

3. Never open.

4. Always open.

Q.

Why is absorption important in living organisms?

1. Absorption of drugs into the bloodstream.

2. Absorption of water and food by intestinal cells in animals.

3. Absorption of water and mineral salts by root hair in plants.

4. All of the above

Q.

Cells which control the transpiration rate of plants are

1. Chlorophyll cells

2. Guard cells

3. Epidermal cells

4. Stomatal cells

Q.

Guard cells fully close the stomatal pore only when water is freely available.

1. True.

2. False.

Q.

Give one word for the following
Structures on leaves through which exchange of gasses occurs.

Q.

Sebaceous glands

Q.

Which part of the plant has stomata?

1. Roots

2. Stem

3. Leaves

4. Fruits

Q.

Which part of the plant takes in carbon dioxide from the air for photosynthesis?

1. Root hair

2. Stomata

3. Leaf veins

4. Sepals

Q.

What are stomata?

Q.

The cell wall of root hair is thin and _____.

1. semi permeable

2. freely permeable

3. impermeable

4. sometimes permeable

Q.

Which of the following solutions is responsible for plasmolysis?

1. Isotonic
2. Hypertonic
3. Hypotonic
4. Both A and C

Q.

In which of the plant, leaf surface may be covered by a thick coating of epidermal hair to reduce transpiration?

1. Cucurbita

2. Banyan

3. Nerium

4. Lavender

Q.

The tiny pores from which leaves take up carbon dioxide from the atmosphere are known as:

1. Chlorophyll

2. Stomata

3. Phloem

4. Xylem

Q. Organ responsible for gaseous exchange in plants is:

1. Roots
2. Flower
3. Leaf
4. Stem

Q. Guard cells are found in:

1. Stomata
2. Ovary
3. Stamen
4. Petals

Q.

Stomata are surrounded by __ cells.

Q.

Complete the following statements by choosing the correct alternative out of those given in brackets.

________ transpiration is a way of maximum water loss by a plant.

1. Cuticular

2. Lenticular

3. Stomata

Q.

After the leaf falls in the autumn, which of the following is the only site of water loss in deciduous trees?

1. Cuticle

2. Lenticel

3. Stomata

4. Bark

Q. Which one of the following are not essential for opening of stomata?

1. Mechanical shock
2. Temperature
3. Cytokinin
4. Rise in pH

Q. An epistomatic leaf is?

1. Sunflower
2. Maize
3. Nymphaea
4. Calotropis

Q. The metal ion involved in stomatal regulation is

1. Fe
2. Mg
3. Zn
4. K

Q. When an epidermal layer of a leaf is observed through a high-powered microscope, it shows that each stoma is surrounded by?

1. Many guard cells.
2. A pair of guard cells.
3. A single guard cell.
4. A pair of epidermal cells.

Q.

Water evaporates through tiny openings present on the leaves known as:

1. tendrils

2. stomata

3. petiole

4. stalk

Q. Which of the following theory of stomatal opening and closing is given by Levitt?

1. Theory of starch - glucose transformation
2. Theory of active $K^{+}$ transport
3. Theory of starch - sugar interconversion
4. None of the above

Q. Which of the following is the constituent of guard cell?

1. Chloroplast
2. All of the above
3. Nucleus
4. Vacuole

Q. Assertion. Stomata remain open during the day time.
Reason. Stomata help in exchange of gases.

Q. The metal ion involved in the stomatal regulation is

1. Iron
2. Magnesium
3. Zinc
4. Potassium

Q. Assertion :Stomata are generally open in light and close in dark Reason: Transpiration is enhanced by heating effect of light

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect