Question

The figure shows the effect of light on the rate of photosynthesis. Based on the graph, answer the following questions :
(a) At which point/s (A, B or C) in the curve is a light limiting factor?
(b) What could be the limiting factor/s in the region A?
(c) What do C and D represent on the curve?

Answer 1

(a) Light is a limiting factor in region A. The rate of a process will be limited by the factor which is in shortest supply which is called the limiting factor. Any change in the level of a limiting factor will affect the rate of

reaction.

(b) Light, carbon dioxide concentration and temperature may be limiting factors in region A.

(c) C represents the saturation of light. Here, light is no longer the limiting factor. The limiting factor here could be carbon dioxide concentration or temperature. D represents the point at which the maximum saturation of carbon dioxide has been reached which the plant requires for photosynthesis.