Question

Energy flow in food chain is always unidirectional. justify this statement.Explain how the pesticides enter a food chain and subsequently get into our body.

Answer 1

1.Because the energy moves progressively through the various trophic levels and is no longer available to the previous trophic level. The energy captured by autotrophs does not revert back to the solar input.
2.Pesticides, used for crop rotection when washed down into the soil/water body, are absorbed by the plant/producer along with water and minerals.
3.Being non-biodegradable these chemicals get accumulated progressively in the food chain and enter our body.
⭐⭐⭐ HOPEFULLY ANSWER⭐⭐⭐

Answer 2

The energy flow through different steps in the food chain is unidirectional. The energy captured by autotrophs does not revert back to the solar input and it passes to the herbivores i.e. it moves progressively through various tropic levels . This energy flow from sun through producers to omnivores is in single direction only.

Pesticides are sprayed to kill pests on food plants. The food plants are eaten by herbivores and along with food, pesticides are also eaten by the herbivores. Herbivores are eaten by carnivores and along with the herbivores, pesticides also enters the body of the carnivores. Man eat both plants and animals and pesticides along with food enters the body of human. Concentration of pesticides increases as we move upward in the food chain and the process is called bio-magnification.