Question

why photosynthesis is considered as the basic energy source for most of living world give reason

Answer 1

photosynthesis is done by the plants which is the main source of life .They produce oxygen through photosynthesis  due to which we are livings so photosynthesis is considered as the basic energy source for most of living world.

Answer 2

since plants contain a cell organelle called chloroplast.. Chloroplast traps sunlight and prepare s food..So the method of preparing food by a leaf is called photosynthesis.. So when this plants are eaten by us we too get the energy..So photosynthesis is considered as the basic energy source for most of living in the world