Which of the following facilitates opening of stomatal aperture?

1.	Decrease in turgidity of guard cells
2.	Radial orientation of cellulose microfibrils in the cell wall of guard cells
3.	Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells
4.	Contraction of outer wall of guard cells

What happens, when a cell is placed in a isotonic solution?
(a) There is not net flow of water towards the inside or outside.

(b) Cells are said to be flaccid.

(c) ${\psi }_P$ becomes positive.

(d) Enlargement and extension growth of cells occur.

The correct statement(s) is/are

1. a only

2. a and b only

3. a, b and c only

4. all are correct

Which one of the following is correctly matched?

1. Passive transport of nutrients-ATP

2. Apoplast- Plasmodesmata

3. Potassium- Readily mobilized

4. Bakanae of rice seedlings-F Skoog

Xylem translocates:

1. Water, minerals salts, some nitrogen and hormones

2. Water only

3. Water and mineral salts only

4. Water, mineral and some organic nitrogen only

To initiate cell plasmolysis, the salt concentration must be :

1. isotonic

2. hypertonic

3. hypotonic

4. atonic

Turgor pressure is also referred to as

1. solute potential

2. water potential

3. pressure potential

4. osmotic potential

The process responsible for the movement of water from roots to all other parts of plants is

1. Evaporation of Water from leaves 

2. Capillary action 

3. Active transport 

4. Both 1 and 2

What is never zero in a cell-

1. Solute potential

2. Water potential

3. DPD

4. Diffusion pressure

Loss of solutes from a cell leads to

1. Increase in water potential

2. Decrease in solute potential

3. Increase in pressure potential

4. All of the above

About _______________ % of the water taken in by roots is lost by transpiration.

1. 100

2. 98

3. 90

4. 60