Question

Biomagnification refers to an increase in the concentration of the toxicant at successive trophic levels. This happens because

• A. A toxic substance accumulated by an organism cannot be metabolised
• B. A toxic substance accumulated by an organism cannot be excreted
• C. A toxic substance gets passed on to the next higher trophic level
• D. All of the above

Answer 1

Answer: (D)

All of the above

Biomagnification, also known as bioamplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain. Biomagnification process occurs when certain toxic chemicals and pollutants such as heavy metals, pesticides or polychlorinated biphenyls (PCBs) compounds go up the food chain by working their way through the environment and into the soil or the water systems after which they are eaten by aquatic animals or plants. Biomagnification occurs in the higher trophic levels of the food chain/web , where exposure to chemicals takes place mostly through food consumption rather than water uptake. Spraying a marsh to control mosquitoes will cause trace amounts of DDT to accumulate in the cells of microscopic aquatic organisms causing accumulation which cannot be metabolized.

So the correct option is 'all of the above'