Stomata: Opening and Closing

Q.

When the guard cells swell due to the entry of water the stomata gets __________ due to the osmotic potential.

1. Closed

2. Flacid

3. Open

4. Rigid

Q.

What happens when sugar is converted into starch in guard cells?

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
5. III and V

Q. Given below is the diagram of stomatal apparatus, identify the part labelled as C

1. guard cells
2. epidermal cells
3. subsidiary cells
4. stomatal pore

Q. Which of the following does not happen during stomatal opening?

1. Accumulation of K+ ions in guard cells
2. Increase of turgor pressure of guard cells
3. Creation of water potential gradient between guard cell and subsidiary cells
4. Increased thickening of inner wall of guard cells

Q.

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

1. cuticles

2. lenticels

3. epidermis

4. stomata

Q. Which of the following does not happen during stomatal opening and closing?

1. Accumulation of K+ ions in guard cell
2. Increase of turgor pressure of guard cell
3. Creation of water potential gradient between guard cell and subsidiary cell
4. Increased thickening of inner wall of guard cell

Q. When stomata open in night only, they are called

1. photoactive stomata
2. scotoactive stomata
3. hydathode
4. all of these

Q. Rate of transpiration and stomatal opening's are measured respectively by

1. porometer and potometer
2. potometer and porometer
3. potometer and tensiometer
4. hygrometer and porometer

Q. Which of the following does not happen during stomatal opening and closing?

1. Accumulation of K+ ions in guard cell
2. Increase of turgor pressure of guard cell
3. Creation of water potential gradient between guard cell and subsidiary cell
4. Increased thickening of inner wall of guard cell

Q. In land plants, the guard cells differ from other epidermal cells in having

1. cytoskeleton
2. mitochondria
3. endoplasmic reticulum
4. chloroplasts

Q.

The adaptability of pteridophytes can be best signified by_________. This is why it is also called as the 'Resurrection Plant'.

1. Cyathea dealbata

2. Equisetum

3. Selaginella lepidophylla

4. Selaginella heterosporous

Q.

In the wall of guard cell, cellulose microfibrils are arranged:

1. Obliquely

2. Transversely

3. Radially

4. Tangently

Q. Arrange the events of the opening of stomata in the correct sequence and choose the correct option accordingly.

I. Lowering of osmotic potential of guard cells.
II. Decline in guard cell solute.
III. Rise of potassium ion level in guard cells.
IV. Guard cells absorb water from neighboring epidermal cells.
V. Guard cells become flaccid.

1. III, I, IV, V
2. I, II, III, IV, V
3. III, I, IV
4. III, I, IV, II, V