Question

Which one of the following statements is NOT correct?

• A. Photophosphorylation is the synthesis of ATP from ADP and inorganic phosphate in the presence of light.
• B. The process through which ATP is synthesised by cells (in mitochondria and chloroplasts) is called phosphorylation.
• C. The Calvin cycle (carboxylation, reduction, and regeneration) occurs in all photosynthetic plants (C3, C4 or any other).
• D. C3 plants have a special type of leaf anatomy, they tolerate higher temperatures, show a response to high light intensities, have high rate of photosynthesis and reduced rate of photorespiration as compared to C4 plants.

Hint:

- C3 plants → high photorespiration, less efficient under heat.
- C4 plants → Kranz anatomy, higher efficiency, lower photorespiration.

Answer 1

The Correct Option is D

Step 1: Evaluate option (A).
Photophosphorylation = formation of ATP using light energy in chloroplasts. Correct.
Step 2: Evaluate option (B).
Phosphorylation = addition of phosphate to ADP to form ATP. This occurs in both mitochondria (oxidative phosphorylation) and chloroplasts (photophosphorylation). Correct.
Step 3: Evaluate option (C).
The Calvin cycle (C3 pathway) is universal in photosynthetic organisms, including C3 and C4 plants. Correct.
Step 4: Evaluate option (D).
This statement incorrectly assigns C4 characteristics to C3 plants. - C4 plants (e.g., maize, sugarcane) show special leaf anatomy (Kranz anatomy), tolerate high temperatures, show reduced photorespiration. - C3 plants (e.g., wheat, rice) lack these features. Thus, (D) is NOT correct. Final Answer: \[ \boxed{D} \]