Q.
The diagram below show the biomagnification of DDT in an aquatic food chain. Choose the correct statement regarding this
I. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels II. High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of eggshell and their premature breaking III. River water may have a very low concentration of DDT, but the carnivorous fish in that river may contain high concentration of DDT, which is still suitable for consumption by human beings Which of the statements given above are correct?
A) I and II
B) I and III
C) II and III
D) I, II and III
Explanation
Heavy metals and persistent pesticides ($e.g.,$ organochlorine or chlorinated hydrocarbons like DDT) pass into food chain and increase in amount per unit weight of organisms with the rise in trophic level due to their accumulation in fat. Higher amounts of pesticide disturb calcium metabolism of birds resulting in thinning of egg shells and their premature breaking that kills the embryos
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.