DDT as an Example of Biomagnification

Q.

Explain the effect of bioaccumulation.

Q. The highest DDT concentration in aquatic food chain shall occur in

1. eel
2. phytoplankton
3. seagull
4. crab

Q. Which one of the following is not correct with regard to DDT?

1. DDT is biodegradable and does not undergoes biomagnification
2. DDT is non-biodegradable and undergoes biomagnification
3. DDT cannot be metabolised by the body
4. DDT is long lived and accumulates in fatty tissues

Q.

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

1. Cobras were feeding exclusively on birds

2. Many of the birds' eggs laid did not hatch

3. Birds stopped laying eggs

4. Earthworms in the area got eradicated

Q. Drinking of mineral water with very low level of pesticides (about 0.02 ppm) for long periods may:

1. produce immunity against mosquitoes
2. cause leukemia (blood cancer) in most people
3. cause cancer of the intestine
4. lead to accumulation of pesticide residues in body fat

Q. DDT residues are rapidly passed through food chain causing biomagnification because DDT is

1. liposoluble
2. moderately toxic
3. Non-toxic to aquatic animals
4. water soluble

Q. Regarding the assertion and reason, choose the correct option.
Assertion [A]: Methyl mercury is a highly persistent kind of pollutant that accumulates in food chains.
Reason [R]: Mercury pollution is responsible for Minamata disease.

1. Both A and R are true and R is the correct explanation for A
2. Both A and R are true but R is not the correct explanation for A
3. A is true but R is false
4. Both A and R are false

Q. The drawback of DDT as a pesticide is:

1. It becomes ineffective only after some time.
2. It is less effective than others.
3. It is not easily/rapidly degraded in nature.
4. Its cost is very high.