Question

Which statement is incorrect about compensation point?

• A. No growth occurs.
• B. Rate of photosynthesis is equal to respiration.
• C. Neither $O_2$ nor $C{O}_2$ is given off.
• D. Occurs when light intensity falls to 20% of normal.

Answer 1

The correct option is A No growth occurs.

The compensation point is the amount of light intensity on the light curve, where the rate of photosynthesis exactly matches the rate of respiration. At this point, the uptake of CO${}_2$ through photosynthetic pathways is exactly matched to the respiratory release of carbon dioxide, and the uptake of O${}_2$ by respiration is exactly matched to the photosynthetic release of oxygen. This point is reached during early mornings and late evenings. Respiration is relatively constant whereas photosynthesis depends on the amount of sunlight. During compensation point, rate of photosynthesis is equal to respiration, neither O${}_2$ nor CO${}_2$ is given off and it occurs when sunlight intensity falls to 20% of normal. So, all these statements are correct. During compensation point, growth of plant occurs. So, this statement is wrong. Thus, option A is correct and other options are incorrect.