Leaving Certificate Biology Practice Test 2026 – Complete Exam Prep

Two or more interconnected food chains are described as a food web. A food chain is a simple, straight-line sequence showing who eats whom, usually from producers up to top predators. But in real ecosystems, organisms often eat more than one kind of prey and are eaten by more than one predator, so energy moves along several pathways. When these feeding links form a network, with multiple connections among species, you get a food web. This gives a more accurate picture of energy flow and ecological relationships, including producers, multiple trophic levels, and decomposers connected through detritus. The other terms don’t capture that network aspect: a niche is the role of an organism in the environment, and a guild is a group of species that exploit the same resource in a similar way but not necessarily connected as a network.