Question

Compensation point occurs

• A. When intensity of light is high
• B. During dark
• C. During morning and evening hours
• D. During mid-night

Answer 1

The correct option is C During morning and evening hours

• 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 $C{O}_2$ 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. At the compensation point, the rate of photosynthesis is balanced to the rate of respiration so that the plant is neither consuming nor building biomass.