Identify the incorrect statement regarding plasmolysis in plant cells:
1. If a plant cell is placed in a hypertonic solution, the plant cell loses water and hence turgor pressure by plasmolysis.
2. If cytorrhysis occurs the plant will wilt.
3. Plasmolysis can be reversed if the cell is placed in a hypotonic solution in many cases.
4. Convex plasmolysis is always reversible.
Which of the cell would be called as ‘flaccid’?
1. A
2. B
3. C
4. A and B
Rocks can be split by inserting dry wooden stalks in the crevices of the rocks and soaking them in water. The physiological basis of this phenomenon is:
1. Imbibition
2. Crenation
3. Cytorrhisis
4. Reverse osmosis
What is incorrect regarding apoplast transport in plants?
1. The apoplast is formed by the continuum of cell walls of adjacent cells as well as the extracellular spaces.
2. Transport velocity is lower in the apoplast than in the symplast.
3. Apoplast transport also accounts for a higher proportion of water transport in plant tissues than does symplastic transport.
4. The apoplastic pathway is also involved in passive exclusion.
Root pressure is caused by:
1. active distribution of mineral nutrient ions into the root xylem.
2. passive distribution of mineral nutrient ions into the root xylem.
3. a lower water potential in soil than the root cells.
4. transpirational pull.
Arrange the following events in the correct chronological order during opening of the stomata:
I. An uptake of potassium ions occurs into the guard cells.
II. A proton pump drives protons (H+) from the guard cells.
III. Diffusion of water occurs into the guard cell through osmosis.
IV. The two guard cells lengthen by bowing apart from one another.
V. Negative ions flux into the guard cells to balance the influx of potassium.
1. I, III, II, IV, V
2. I, II, V, III, IV
3. II, I, V, III, IV
4. II, V, I, III, IV
When the roots begin to sense a water shortage in the soil, abscisic acid (ABA) is released. The increase of which of the following ions in the cytosol of the guard cells is responsible for ultimately bringing about a closure of stomata?
1. Calcium
2. Magnesium
3. Potassium
4. Hydrogen
Various factors affect stomatal movement. Which of the following is not a correct relation between the factor and stomatal movement?
1. | Stomata open in the presence of light and close in darkness. |
2. | Stomata tend to open more with an increase in temperature especially up to 30C. |
3. | Water stress induces stomatal closure. |
4. | With an increase in carbon dioxide concentration inside the leaf, the stomata open. |
Mass flow of liquid water from roots to the leaves is primarily driven by:
1. Root pressure
2. Capillary action
3. Water potential differences
4. Active transport
If a plant is incapable of bringing in enough water to remain in equilibrium with transpiration, it can result in:
1. Cavitation
2. Crenation
3. Immediate death of root
4. Opening of stomata