Question

Which of the following causes bio-magnification?

• A. ${SO}_2$
• B. Mercury
• C. DDT
• D. Both (b) and (c)

Answer 1

Answer: (D)

Both (b) and (c)

Biomagnification refers to increase in concentration of toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level. This phenomenon is well-known for mercury and DDT.