Ddt was banned from use as a pesticide in the united states because

a. it caused the eggs of fish-eating birds to become thin and fragile.

b. it was washed by rain into streams, rivers, lakes, and ponds.

c. it was ingested by fish and other aquatic animals.

d. all of the above.

d. All of the above.

Explanation:

DDT () is tasteless and colorless chemical compound it is specifically used as an insecticide over the agricultural crops. It is responsible for causing the phenomena of biomagnification. It can be define as the increase in concentration of the toxic substance among the levels of the food chains. The trophic level which is at the highest level is the most affected one because of the fact that the toxic get accumulated in high concentration.

The DDT is associated with the improper development of the eggs of the fishes and birds as it is involved in early hatching of eggs hence, this may result in decline in the population of fish and birds.

As it is used in the agriculture field as an insecticide it may be washed by the surface runoff caused by the rain water and is likely to pollute the water of rivers, lakes and ponds.

It is a deadly poison which when consumed by the living beings can be lethal and when it remains undigested in the body may result in deadly symptoms.

On the basis of the above explanation, d. All of the above. is the correct option.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.