Stomata: Opening and Closing

Q.

Formation of drops of water along leaf margin due to excessive root pressure is called ___.

Q.

The cell wall of root hair is thin and _____.

1. semi permeable

2. sometimes permeable

3. freely permeable

4. impermeable

Q.

Stomata of a plant open due to:

1. Influx of potassium ions

2. Efflux of potassium ions

3. Influx of hydrogen ions

4. Influx of calcium ions

Q.

Water evaporates from tiny pores on leaves. These pores are known as

1. cuticles

2. lenticels

3. epidermis

4. stomata

Q.

Stomatal apparatus does not include ________.

1. Substomatal cavity

2. Guard cell

3. Subsidiary cell

4. Stoma

Q.

Select the correct events leading to opening of the stomata.
I. Decline is guard cells solutes.
II. Lowering of osmotic potential of guard cells.
III. Rise in potassium levels in guard cells.
IV. Movement of water from neighbouring cells into guard cells.
V. Guard cells becoming flaccid.
Select the correct answer using the codes given below.

1. I and V

2. II, III and IV

3. I, III and IV

4. II, IV and V

Q.

In a hypertonic solution, the water molecules will move from outside the cell to inside.

1. True

2. False

Q.

Which of the following cells are not related to the structure of stomata?

1. Guard cells

2. Accessory cells

3. Epidermal cells

4. Sclerenchymatous cells

Q.

In CAM plants, stomata are:

1. Open during the day and close at night

2. Open during night and close during day

3. Always open

4. Never open

Q. Which of the following get accumulated in the vacuoles of guard cells during stomatal opening?

1. Starch, potassium and chloride ions
2. Malate, potassium and chloride ions
3. Malate, sodium and potassium ions
4. Water, calcium and magnesium