Food Chains&

Food WebsUNIT 5: POPULATIONS & ECOSYSTEMS

What is a Food Chain?

A food chain is the path by which energy passes from one living thing to another.

What’s in a Food Chain?

Producers

Consumers

Decomposers

All energy on earth starts from the sun.

(producers) use energy from sun, carbon dioxide, and water to make food

store energy in leaves, stems and roots

all other living things on earth get energy from plants.

consumers any form of life on earth that must eat other things to survivecannot make their own food

labeled by the number of steps they are away from plants, in the food chain

primary consumer eat plants to survive

get energy directly from plants

Ex: caterpillar eats a leaf; elephant eats bark of a tree; cow eats grass; squirrel eats nuts

secondary consumer organisms that eat primary consumers (plant eaters) to survive

get their energy from plants second-hand

Ex: owl eats mouse that eats berry; spider eats insect that eats leaf

tertiary consumer organisms that eat secondary consumers to survive

get their energy from plants third-hand

EX: hawk eats the fish, that ate the smaller fish, that ate the seaweed

top consumer not eaten by any other consumer on top of the food chain

can be primary, secondary or tertiary consumer

decomposers break down remains of dead organisms

help release trapped energy in dead organism back to the earth.

Let’s Lookat a

Food Chain

Types of Food Chains Aquatic- Water-related food chains with sea plants and animals

Terrestrial- Land-related food chains with land plants and animals

What is a Food Web?A more realistic way of looking at the relationship of plants and animals in an environment Several food chains linked together

Food Webs How many food chains can you make from this food web?