With reference to food chains in ecosystems, consider the following statements: 1. A food chain illustrates the order in which a chain of organisms 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 statements given above is/are correct?

A food chain illustrates the trophic relationships between different species in an ecosystem, showing the flow of energy from producers to consumers of various levels. Food chains involve interactions between different species at different trophic levels, not typically within the population of a single species (unless referring to cannibalism, which isn't the primary representation). While the number of organisms at each level can be represented in an ecological pyramid (like the pyramid of numbers), a simple food chain diagram does not illustrate the numbers of organisms eaten.