Which one of the following group of organisms forms a food chain ?

A food chain is a linear sequence of energy transfer from producers to higher trophic levels [2]. It must begin with a producer, typically a green plant that creates its own food via photosynthesis [5]. In the provided options, 'Grass, goat and human' represents a valid grazing food chain. Grass serves as the primary producer [3]. The goat acts as a primary consumer (herbivore) that feeds on the grass [3]. Finally, the human acts as a secondary consumer by consuming the goat [2]. Other options are invalid because they either lack a logical predator-prey sequence (e.g., humans do not typically eat grass, and cows do not eat goats) or include non-biological roles like a 'tree cutter' [2]. This sequence correctly illustrates the flow of energy from the first trophic level to subsequent levels [4].

Sources

1. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 1: BASIC CONCEPTS OF ENVIRONMENT AND ECOLOGY > FOOD ChAIN. > p. 29
2. [5] https://education.nationalgeographic.org/resource/food-chain/
3. [3] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 2: Functions of an Ecosystem > Sl{ANl<Ari ffi IASACADEMY ,:: ' > p. 13
4. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 2: Functions of an Ecosystem > i) Grazing food chain > p. 12
5. [4] https://education.nationalgeographic.org/resource/food-web/