Opening and closing of stomata are due to the:
1. Hormonal change in guard cells
2. Change in Turgor pressure of guard cells
3. Gaseous exchange
4. Respiration
Mark the statements true (T) or false (F).
A. Less than 1 percent of water reaching the leaves is used in photosynthesis and plant growth.
B. Cellulose microfibrils of guard cells are oriented longitudinally, making it easier for the stoma to open.
C. Transpiration can create pressure sufficient to lift a xylem sized column of water over 130 metres high.
D. C4 plants lose only half as much water as a C3 plant for the same amount of CO2 fixed.
A B C D
1. F T F T
2. F T F F
3. T F T T
4. T F F T
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 |
The inner wall of guard cell is not
(1) Thin
(2) Elastic
(3) Towards the pore or stomatal aperture
(4) All of these