“Energy flow in food chains is always unidirectional.” Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.
● Sun is the ultimate source of energy in an ecosystem. Energy always flows from sun to the producer through photosynthesis. Producers such as green plants make food for other organisms. From producers energy is transferred to different consumers. Thus, energy always flow from sun to producer and then to consumers.
● DDT is an insecticide and is non-biodegradable compound.
Once this insecticide sprayed in the environment, it stays for very long time and through food chain into the organisms.
According to the concept of biomagnification, the maximum accumulation of a non-biodegradable pollutant is maximum in the highest trophic level.
Hence, DDT gets accumulates at each trophic level and since, man is at the highest trophic level, there is maximum accumulation of DDT observed in them.