Question

The flow of DDT through the food chain, culminating in the deaths of cats in Borneo, represents the:
A. number of links in an ecosystem.
B. need to understand how resources are passed through an ecosystem.
C. need for stringent testing of anything that might affect the environment.
D. All of the above

Answer 1

Hint: Our ecosystem is completely interdependent on each other that's why organisms feed on each other and depend on each other for shelter, communication, multiplication as well. This cycle of dependence however, sometimes leads to passage of harmful substances that were present in one organism to another.


Complete step by step solution:
In any ecosystem, there is interaction between organism to organism or between organisms and the environment. The food chain where one organism feeds on next is an orderly representation of this interaction. In those chains, a lower species gets consumed by an organism of a higher species and so on.

When certain harmful substances such as chemicals are supplied among any group of organisms then the ones who will feed on them have a high chance of consuming those substances as well. One such example is the consumption of DDT by organisms.

DDT is a chemical compound that stands for Dichlorodiphenyltrichloroethane. It does not have odor or color or taste that's why organisms are unable to realize its presence. It was developed by scientists to control the spread of mosquitoes, mosquito borne diseases and pests so that crop damage can be prevented.

However, it's harmful to the health of higher organisms. It generally enters the food chain by surface runoff or grasslands etc, and then they begin getting accumulated in organisms one after another. The slow accumulation of DDT in subsequent trophic levels leads to their accumulation in the fatty tissues of the organisms. This is known as bioaccumulation.
This is fairly harmful for aquatic lives as well.

Thus, the serial deaths of cats in Borneo due to the flow of DDT in food chains implies that there is need for stringent testing of anything that might affect the environment. So the correct option is C. .


Note: DDT concentration is found highest in organisms at higher levels in a food chain. This is a result of constant accumulation of the product in their tissues which goes on increasing and that process is known as biomagnification. DDT can be a good insecticide but it has many harmful effects on the body.