Question

Variegated leaf experiment helps to demonstrate the essentiality of ____ for photosynthesis -
a. Carbon Dioxide
b. Light
c. Chlorophyll
d. Oxygen

Answer 1

Hint: Photosynthesis is the procedure in which green plants mainly convert energy from the sun’s light into usable, chemical energy. Plants need energy for growth, reproduction, and defense. Glut energy, created from photosynthesis, is accumulated in plant tissue as starch. Starch is a white and powdery substance. It stores glucose, which plants use for food.

Complete answer:
The presence of starch in a leaf is consistent evidence of photosynthesis because starch formation requires photosynthesis. The variegated leaf experiment helps to exhibit that chlorophyll (pigment present in the green parts of plants) is necessary for photosynthesis.

This experiment involves looking for starch creation in two leaves – a variegated leaf or a leaf that was partially roofed with black paper, and one that was exposed to light. The Starch is formed from glucose made during photosynthesis. Parts of the leaf with the chlorophyll should turn blue-black when iodine is added showing the starch is present.

This, in turn, proves that photosynthesis happened. The white areas of the leaf in absence of chlorophyll could not photosynthesize. This means they could not create glucose and turn this to starch. Therefore, when getting tested with iodine, these areas should stay pale.

Hence, the correct answer is option (C).

Note: In addition to giving plants their green color, chlorophyll is very important for photosynthesis as it helps to control the energy of sunlight into chemical energy. With photosynthesis, chlorophyll grasps energy and then transforms water and carbon dioxide into oxygen and carbohydrates. The procedure of photosynthesis switches solar energy into a usable form for plants and the animals that consume them, forming the basis of some food chains.