If a plant is releasing CO2 and taking in oxygen during the day, does it mean that there is no photosynthesis ? Justify your answer.

Question

If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.

Answer 1

Release of CO2 and intake of O2 gives evidence that either photosynthesis is not taking place or its rate is too low. Normally during day time, the rate of photosynthesis is much more than the rate of respiration. So, CO2 produced during respiration is used up for photosynthesis hence CO2 is not released.