Question

flow of energy in a food chain is unidirectional. please explain this question with example

Answer 1

Being non-biodegradable these chemicals get accumulated progressively in the food chain and enter our body. ... As human beings occupy the top level in food chain, These chemicals get accumulated in our ...

Answer 2

When sunlight is absorbed by plants, most of the energy is lost as heat to the environment, few goes for respiration ,reproduction ,etc.

Therefore only 10%of energy is available for primary consumers.Similar process happen for all organisms of food chain.
Therefore energy passed once cannot flow back.
For ex grass_deer_lion.
If grass has 1000J of energy deer will have 100J and lion will have 10J