Are the following statements true or false? Give reason in support of your answer.

(a) The rate of photosynthesis continues to rise as long as the intensity of light rises.

(b) The outside atmospheric temperature has no effect on the rate of photosynthesis.

(c) If you immerse a leaf intact on the plant in ice cold water, it will continue to photosynthesise in bright sunshine.

(d) Destarching of the leaves of a potted plant can occur only at night.

(e) If a plant is kept in bright light all the 24 hours for a few days, the dark reaction (biosynthetic phase) will fail to occur.

(f) Photosynthesis is considered as a process supporting all life on earth.

(a) False
Corrected statement — Photosynthesis increases with the light intensity up to a certain limit only, and then it gets stabilised at the point S'(0.02% CO₂).

(b) False
Corrected statement — The atmospheric temperature is an important external factor affecting photosynthesis. With the rise in temperature, the rate of photosynthesis rises. This rise occurs up to the optimum temperature of 35°C (maximum suitable temperature when the photosynthesis occurs best) after which the rate falls and stops above 40°C.

(c) False
Corrected statement — Ice cold water will hamper the process of photosynthesis in the immersed leaf, even if there is sufficient sunshine because the temperature is an important factor for the rate of photosynthesis.

(d) False
Corrected statement — For destarching, the potted plant can be kept in a dark room for 24-48 hours. During this period, all the starch will be removed from the leaves and stored in the storage organs.

(e) False
Corrected statement — If a plant is kept in bright light all the 24 hours for a few days, the dark reaction (biosynthetic phase) will continue to occur because the dark reaction is independent of light and it occurs simultaneously with the light dependent reaction.

(f) True