Unit 2: Adaptations of Organisms - Food Chains and Webs

Food Chains

• Food chains are visual diagrams illustrating the relationships between producers, consumers, and decomposers.
• They depict who eats what within an ecosystem.

Producers

• Producers obtain energy from the sun through photosynthesis.

Consumers

• Consumers acquire energy by consuming other organisms.

Decomposers

• Decomposers gain energy from dead or decaying organisms.

Energy Flow in Food Chains

• Arrows in a food chain indicate the direction of energy flow.
• The arrow points from the organism being eaten to the organism consuming it.

Consumer Order

• Animals that directly consume producers are called first-order, or primary, consumers, and are herbivores.
• Animals that consume primary consumers are called second-order, or secondary, consumers, and they can be carnivores or omnivores.
• Animals that consume secondary consumers are called third-order, or tertiary, consumers.
• Tertiary consumers are at the top of the food chain and rarely preyed upon.

Food Webs

• Food webs consist of multiple interconnected food chains within an ecosystem.

Food Chains vs. Food Webs

• Similarities:
  • Both depict who eats what in an ecosystem.
• Differences:
  • Food chains illustrate only one predator-prey pathway.
  • Food webs display multiple food chains concurrently.