Question

How many food chains are there in the food web shown above?
A) 2
B) 3
C) 5
D) 7

Answer 1

Hint:-An ecosystem includes all abiotic (soil, water bodies, etc.) elements and biotic (plants, animals, microbes) elements in a given geographic area. For an ecosystem to function properly all these elements need work in a concerted manner. The biotic elements in any ecosystem can be divided into three main categories- the producers, the consumers, and the decomposers.

Complete Answer:-Number of food chains in an ecosystem together form a food web. A food web is way more complex because of the interconnected food chains.
A food chain depicts a linear relationship between the producers, consumers, and the decomposers in an ecosystem. In a food chain, each biotic element is assigned a trophic level which basically is the organism’s position in the food chain. Producers (plants, phytoplankton) i.e. the organism that can produce its own food is placed in the first trophic level. Primary consumers occupy the next trophic level. Primary consumers feed on the producers (deer, grasshopper). The secondary consumers (frog, python, and lion) occupy the next trophic level. The tertiary consumers (lion, python) who feed on the secondary consumers occupy the next trophic level. This is an example of a grazing food chain. Most of the food chains are short but depending upon the ecosystem the number of trophic levels varies.
In this question, five food chains are depicted-

The correct option is (C).

Note:- Apart from representing the position of an organism, food chains depict the transfer of energy from one trophic level to another.
If any species in any of the trophic levels go extinct, the food chain is disrupted and the ecosystem is no longer balanced. In the same way, an unchecked increase in the population of an organism at any trophic level will cause the same imbalance.