13.4 Food Chains And Food Webs

SPONGE

Name a keystone species, and predict what might happen if that species went extinct.

13.4 Food Chains And Food Webs

KEY CONCEPT Food chains and food webs model the flow of

energy in an ecosystem.

13.4 Food Chains And Food Webs

• A food chain is a model that shows a sequence of feeding relationships. – A food chain follows the connection between one

producer and a single chain of consumers within an ecosystem.

DESERT COTTONTAILGRAMA GRASS HARRIS’S HAWK

13.4 Food Chains And Food Webs

• A food web emphasizes complicated feeding relationships and energy flow in an ecosystem.

ENERGY

13.4 Food Chains And Food Webs

At your table please describe these types of consumers:

• Herbivores?

• Carnivores?

• Omnivores?

• Decomposers?

13.4 Food Chains And Food Webs

• Consumers are not all alike.

– Herbivores eat only plants. Ex: grasshopper– Carnivores eat only animals. Ex: Lion– Omnivores eat both plants and animals. Ex: Bears– Detritivores eat dead organic matter. Ex: Worms, slugs

– Decomposers are detritivores that break down organic or dead matter into simpler compounds. Ex: bacteria,

Fungi

carnivoredecomposer

13.4 Food Chains And Food Webs

• Specialists are consumers that primarily eat one specific organism (they only eat one thing) Ex: Bamboo is 99% of a panda’s diet

• Generalists are consumers that have a varying diet (they eat a lot of different things) Ex: Gray wolf eats elk, moose, deer, and mice

13.4 Food Chains And Food Webs

• Trophic levels are the nourishment levels in a food chain.

13.4 Food Chains And Food Webs

• Carnivores that eat carnivoresEx: Hawk eating rabbit

• Carnivores that eat herbivoresEx: Rabbit eating grasshopper

• Herbivores that eat producersEx: grasshopper eating grass

ENERGY

13.4 Food Chains And Food Webs

Omnivores, such as humans that eat both plants and animals, may be listed at different trophic levels in different food chains.

• If you are eating a salad you are….?• a primary producer (omnivore eating a

producer)

• If you are eating a hamburger you are….?• a secondary producer (omnivore eating a

herbivore)

• If you are eating shark soup, you are….?• a tertiary consumer (omnivore eating a

carnivore)