Following are the statements about common feature of drought avoidance in plants
A. Early stomata closure
B. Efficient root system
C. Lipid deposition on foliage
D. Reduction in water uptake
E. Straightening of leaves
Choose the correct answer from the options given below:
Show Hint
Drought avoidance mechanisms are active plant adaptations designed to conserve water (such as stomatal closure and waxy leaves) or increase water intake (such as deep roots).
Step 1: Understanding the Concept:
Plants have evolved various mechanisms to survive drought stress, which can be grouped into:
Escape (completing the life cycle before stress occurs)
Tolerance (surviving low water tissue potential)
Avoidance (maintaining high water potential under dry conditions) Detailed Explanation:
Let us evaluate each statement to identify drought avoidance mechanisms:
- A. Early stomata closure: When soil moisture declines, plants synthesize abscisic acid (ABA), which signals the stomata to close.
This reduces transpiration water loss, helping the plant conserve water and avoid drought. (Correct)
- B. Efficient root system: A deep, branched, and highly efficient root system allows the plant to tap water from deeper soil layers, maintaining its water balance during dry spells. (Correct)
- C. Lipid deposition on foliage: Depositing a thick layer of cuticular wax or lipids on the leaf surface reduces cuticular transpiration, helping the plant retain water. (Correct)
- D. Reduction in water uptake: A reduction in water uptake is a physical consequence of dry soil, not an active adaptation used by the plant to avoid drought. (Incorrect)
- E. Straightening of leaves: Under water stress, plants roll or wilt their leaves to reduce the surface area exposed to sunlight, lowering transpiration.
Straightening or expanding leaves would increase water loss, worsening drought stress. (Incorrect)
Thus, statements A, B, and C describe drought avoidance mechanisms. Step 2: Final Answer:
The correct drought avoidance features are A, B, and C only.
