Question

Read the following statements (I - III) related to food webs in ecosystems, and select the correct statements ?

I. A Food web is a group of food chains interlinked and interdependent.
II. Food chains are linear and food webs are complex.
III. In a food web, the same food resource can be a part of more than one food chain.

• A. I and II only
• B. II and III only
• C. I, II and III
• D. I and III only

Answer 1

The correct option is C I, II and III

A food chain is a chronological series of organisms each depending on others for food. A food web is a network of food chains interconnected to each other and are interdependent. Hence statement I is correct.

Figure : Food chain

In a food web, one organism can consume multiple organisms and can itself be consumed by multiple organisms. They help to understand ecological interactions among organisms and flow of energy in a better way in the ecosystem.

On the other hand, food chains are linear, showing how each living thing gets food, and how nutrients and energy are passed. It implies the transfer of food energy from its source in plants through herbivores to carnivores. A food web is the natural interconnection of food chains and generally a graphical representation. It is complex. Hence statement II is correct.

Figure : Food web

A food web illustrates all possible transfers of energy and nutrients among the organisms in an ecosystem, whereas a food chain traces only one pathway of the food. If any intermediate organisms are removed from a food chain, then succeeding links in the chain will be largely affected. On the other hand, the food web provides multiple alternatives for food to the organisms thereby, increasing the chances of survival. It gives more stability to the ecosystem. Hence statement III is correct.