Question

What is the difference between food chains and food webs?
Food webs show the flow of energy from producers to consumers, and food chains show the flow of energy from consumers to producers.
Food chains show a single path of energy in an ecosystem, and food webs show overlapping pathways of energy in that ecosystem.
About ten percent of the energy is passed on to the next trophic level in food webs, but in food chains, about ninety percent is passed on to the next trophic level.
Heat is lost when energy is passed on to the next trophic level in food chains, but in food webs, heat is not lost when energy is passed on to the next trophic level.

Answer 1

The correct choice is:
Food chains show a single path of energy in an ecosystem, and food webs show overlapping pathways of energy in that ecosystem.

Why:
- A food chain is a linear sequence (producer → primary consumer → secondary consumer → …) showing one pathway of energy flow.
- A food web is many interconnected food chains showing multiple feeding relationships and overlapping energy pathways in an ecosystem.

Why the others are wrong:
- The first option reverses the direction of flow (energy flows from producers to consumers, not consumers to producers).
- The third option misstates energy transfer: the ~10% rule is a general estimate for any trophic transfer, not something that differs between chains and webs.
- The fourth option is false: energy is lost as heat at each trophic transfer in both chains and webs (due to respiration and inefficiencies).