Q. In an area where DDT had been used extensively, the population of birds declined significantly because
A) Many of the birds eggs laid, did not hatch
B) Birds stopped laying eggs
C) Earthworms in the area got eradicated
D) Cobras were feeding exclusively on birds
Explanation
[Solution from source] DDT accumulates through biomagnification in fish-eating birds and disturbs their calcium metabolism, so egg shells become thin and break before hatching; many eggs laid therefore did not hatch. Birds did not stop laying eggs altogether. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.