Give reasons for the following:

(a) Solar energy is available in plenty but animals cannot use it directly whereas the plants can.
(b) Life on earth depends on the sun.

(a) Animals do not have chloroplasts in the cells of their body. So, they cannot convert solar energy into chemical energy (food).
Plants have chloroplasts (containing chlorophyll pigment) in their cells which can trap solar energy for producing food during photosynthesis.
(b) All living things constantly need energy to be alive. They get the energy in the form of food. The food directly or indirectly comes from the green plants. The green plants trap light energy coming from the sun to produce food during photosynthesis.
Green plants also produce O₂ during photosynthesis which is necessary for organisms for respiration.