Question

The plants are kept in dark before determining the factor essential for photosynthesis. This is done

• A. To measure the exact effect of that factor on photosynthesis
• B. To give the plant a break
• C. To allow the plant to store it's food
• D. Both A and B
  

Answer 1

The correct option is A To measure the exact effect of that factor on photosynthesis

To determine the effect of any factor like CO${}_2$, sunlight, chlorophyll, on photosynthesis of the plant, the plant will be kept in a dark room or cupboard for 48 hours to eliminate the starch from the leaves of the plant, which was previously formed through photosynthesis. This process is known as destarching. After destarching, the effect of that factor on the formation of starch can be easily studied.