Rate of diffusion of substances is affected by all, except
1. Gradient of concentration
2. Temperature but not pressure
4. Both temperature and pressure
The cell gets swell up, when placed in
1. Hypertonic solution
2. Hypotonic solution
3. Ultratonic solution
4. Isotonic solution
Read the following statements (with respect to imbibition):
A. Special type of diffusion when water is absorbed by solid colloids.
B. There is enormous increase in volume of imbibant.
C. Affinity between the absorbant and absorbate is a pre-requisite.
D. Water movement occurs against the concentration gradient.
1. Only A is correct
2. Only A and B are correct
3. Only A, B and C are correct
4. All are correct
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
Elements most readily mobilized are
1. P, S and Ca
2. N, K and P
3. N, P and Fe
4. S, Zn and P
Most of the movement in roots through apoplast is due to
(1) Cortical cells are loosely packed and hence no resistance to water movement
(2) Endodermal cells are loosely packed and hence no resistance to water movement
(3) Pericycle cells are loosely packed and hence no resistance to water movement
(4) Medullary cells are loosely packed and hence no resistance to water movement
Mass flow or bulk flow system is the movement of substances in bulk or en masse from one point to another point as a result of
(1) Pressure Difference between two points
(2) Osmotic gradient between two points
(3) Concentration gradient between two points
(4) Cannot be predicted
In germination of seed, what is absorbent?
Osmotic pressure is the
(1) Pressure required to stop the water diffusing in
(2) Function of solute concentration
(3) More the solute, more is the pressure needed to stop endosmosis
(4) All of these
Molecules moves across a membrane independent of other molecules, by the means of membrane protein, the process is called