Question

The maintenance functions of all living organisms must go on even when they are not doing anything particular. Even when we are just sitting in a class or even asleep, this maintenance job has to go on. These maintenance processes require energy to prevent damage and break-down of cells and tissues, which is obtained by the individual organism from the food prepared by the autotrophs, called producers.

What are the differences between autotrophic nutrition and heterotrophic nutrition?

The autotrophic mode of nutrition requires

What are the necessary conditions for autotrophic nutrition and what are its by-products?

What are trophic levels? Why are autotrophs considered to be at the first trophic level of all food chains? State the reason for limited number of trophic levels in nature.