Food chain

Definition

A food chain is a linear sequence of organisms where each is eaten by the next member in the chain. It shows the flow of energy and nutrients from one organism to another within an ecosystem.

5 Must Know Facts For Your Next Test

1. Food chains start with producers, usually photosynthetic organisms like plants or algae.
2. Consumers in a food chain are classified as primary, secondary, and tertiary based on their feeding relationships.
3. Decomposers, such as bacteria and fungi, play a critical role in breaking down dead organic matter and recycling nutrients back into the ecosystem.
4. Energy transfer between trophic levels in a food chain is typically only about 10% efficient; most energy is lost as heat.
5. Food chains can be disrupted by environmental changes, which can lead to shifts in population dynamics and ecosystem stability.

Review Questions

• What is the role of producers in a food chain?
• Why are decomposers important for nutrient cycling in an ecosystem?
• Explain why only about 10% of energy is transferred from one trophic level to the next in a food chain.

Related terms

trophicLevel: A position that an organism occupies in a food chain, such as primary producer or tertiary consumer.

foodWeb: A complex network of interconnected food chains within an ecosystem showing multiple pathways of energy flow.

biomagnification: The process whereby certain substances, such as toxins, become more concentrated at higher trophic levels within a food chain.