With reference to food chains in ecosystems, consider the following statements: 1. A food chain illustrates the order in which a chain of organism feed upon each other. 2. Food chains are found within the populations of a species. 3. A food chain illustrates the numbers of each organism which are eaten by others. Which of the statement given above is / are correct?

A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another [1]. Statement 1 is correct as it accurately describes this feeding order [3]. Statement 2 is incorrect because food chains represent interactions between different species within a community or ecosystem, rather than within a single population of one species [5]. Statement 3 is incorrect because a food chain illustrates the flow of energy and the sequence of 'who eats whom' [4], but it does not inherently illustrate the specific numbers of organisms at each level. While ecological pyramids of numbers can represent such data, a standard food chain is a qualitative representation of energy pathways [5]. Therefore, only the first statement is a defining characteristic of a food chain.

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 2: Functions of an Ecosystem > 2.2. FOOD CHAIN > p. 11
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 13: Our Environment > 13.1.1 Food Chains and Webs > p. 210
3. [5] https://www.epa.gov/sites/default/files/documents/foodchainsandfoodwebs.pdf
4. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 12: How Nature Works in Harmony > Activity 12.8: Let us trace and link > p. 200
5. [4] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 2: Functions of an Ecosystem > 2.3. FOOD WEB > p. 12