Question

Identify A, B, and C in the given Hatch and Slack pathway diagram:

 

• A. A – Fixation, B – Regeneration, C – Decarboxylation
• B. A – Regeneration, B – Fixation, C – Decarboxylation
• C. A – Decarboxylation, B – Regeneration, C – Fixation
• D. A – Fixation, B – Decarboxylation, C – Regeneration

Hint:

The efficiency of the C4 pathway in minimizing photorespiration is pivotal in conserving water and energy in plants, making it a key adaptation in arid climates.

Answer 1

The Correct Option is D

Step 1: Analyzing the Hatch and Slack pathway components.
The diagram illustrates the C4 photosynthesis pathway which efficiently captures carbon in hot and dry environments. A, located in the mesophyll cells, represents Fixation, where atmospheric CO2 is initially fixed into a four-carbon compound (e.g., oxaloacetate) by the enzyme PEP carboxylase.
Step 2: Understanding Decarboxylation and Regeneration.
B in the diagram, occurring in the bundle sheath cells, involves Decarboxylation where the four-carbon compound releases CO2 to be used in the Calvin cycle. C represents Regeneration, where the remaining three-carbon compound (e.g., pyruvate) returns to the mesophyll cells to regenerate phosphoenol pyruvate (PEP), thus completing the cycle.