Question

In an area where DDT had been used extensively, the population of birds declined significantly because

• A. Birds stopped laying eggs.
• B. Earthworms in the area got eradicated.
• C. Cobras were feeding exclusively on birds.
• D. Many of the birds eggs laid, did not hatch.

Answer 1

The correct option is D Many of the birds eggs laid, did not hatch.

DDT was commonly used as a pesticide. On the prolonged use of the pesticide, there were many side effects observed. The plants were accumulated with these chemicals and the pesticide entered the food chain. The birds were affected due to the presence of the pesticide. The birds lay the eggs but due to the effect of this chemical, the egg shells were very thin. The shell break and the embryos did not develop. So, there was a failure in the hatching of the birds from the eggs.

Thus, the correct answer is option D.