Question

What among the following is likely to have the highest levels of D.D.T depositions in its body?
A. Eel
B. Crab
C. Seagull
D. Phytoplankton.

Answer 1

Hint: DDT is a non biodegradable pollutant. It's an acronym for dichlorodiphenyltrichloroethane. The level of DDT increases as the food chain advances. This implies that top carnivores have high DDT levels. Tertiary consumers form the highest trophic level, examples of which are seagulls, etc.

Complete step-by-step answer:

DDT, also known as 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, is a synthesized insecticide that belongs to the group of organic halogen compounds and therefore is highly toxic to a vast variety of insects as a contact poison that appears to exert its impacts by disorganizing the nervous system.
DDT levels rise as the food chain advances. This means that primary consumers will have higher DDT concentrations than producers, secondary consumers will have higher concentrations than primary consumers, and so on.
The top carnivore will have the highest concentrations. With each successive trophic level, consumers consume more food to meet their energy requirements.
As a result, DDT tends to accumulate in higher concentrations at each trophic level. This is known as biomagnification.
The highest trophic level is formed by tertiary consumers. Seabirds such as seagulls consume a variety of many other organisms such as squid, fish, and crustaceans, making them tertiary consumers. The increasing order of DDT concentration or levels of the food chain is given below:
Producers < Primary consumers < Secondary consumers < Tertiary consumers.
Hence, option C is correct.

Note: Phytoplanktons are autotrophs. Microscopic plants such as phytoplanktons occupy the first trophic level.