question_answer

The graph shows the relation between light intensity and the giving off and taking up of carbon dioxide by the leaves of a plant. Why is most carbon dioxide given off when the light intensity is zero units [Kerala PMT 2004]

A) Because it is just the start of the experiment

B) Only respiration is taking place at this intensity of light

C) Only photosynthesis is taking place at this intensity of light

D) The rate of photosynthesis is equivalent to the rate of respiration

E) The rate of photosynthesis is more than the rate of respiration