Before You Begin
Question #45933
The Question
Read the following statements regarding plant growth regulators, source-sink dynamics, and photosynthetic metabolic balance:
I. A high Cytokinin to Auxin ratio in a tissue culture medium favors shoot differentiation, thereby establishing a strong metabolic source. II. During stress-induced leaf senescence, the light compensation point shifts to a higher light intensity due to the degradation of the photosynthetic apparatus. III. At the light compensation point, the rate of gross photosynthesis equals the rate of cellular respiration, resulting in zero net CO2 exchange. IV. Cytokinins naturally accelerate leaf senescence by promoting the rapid mobilization of nutrients away from mature leaves.
Select the correct option:
Options
- A.
Statements I and IV are correct
- B.
Statements II and III are correct
- C.
Statements I, II, and III are correct
- D.
Statements II and IV are correct
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Meristematic_Activity|Photosynthate_Allocation|Senescence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize 'High Cytokinin = Shoots' but fail to link it to NCERT Transport concepts (developing shoots are sinks, not sources).
Furthermore, understanding the LCP requires balancing two opposing rates; recognizing that a failing photosynthetic apparatus (senescence) requires more light to reach the break-even point is a high-level application.
Finally, confusing the senescence-delaying property of Cytokinins with senescence-promoting hormones is a classic functional overlap trap.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Respiration in Plants - Class 11 |
| Concept | Compensation Point Logic |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |