Question

What is true about compensation point in C${}_3$ and C${}_4$ plants?

• A. Compensation point of C${}_3$ plants is higher.
• B. Compensation point of C${}_4$ plants is higher.
• C. It is equal.
• D. None of these as it is variable.

Answer 1

The correct option is A Compensation point of C${}_3$ plants is higher.

CO${}_2$ compensation point: It is the point where the rate of photosynthesis becomes equal to the rate of respiration (Net photosynthesis is zero).

CO${}_2$ compensation point for C${}_4$ plants is 0-10 ppm. It is low due to the high affinity of PEP carboxylase.

CO${}_2$ compensation point for C${}_3$ plants is 25-100 ppm.

Hence, the correct answer is 'Compensation point of C${}_3$ plants is higher'.