1. Food Webs & Ecological Pyramids
(text ref. page 42-47)

2. Learning Goals
We are learning the difference between food chains and webs.
We are learning the different feeding roles in an ecosystem.

3. Video: Bill Nye the Science Guy)
Watch the Bill Nye the Science Guy “Food Webs” video

4. Ecological Niches
ecological niche: the function a species serves in an ecosystem including what it feeds on, what eats it and how it behaves
ex. a black bear

5. Types of Organisms in Ecosystems
Producers: organisms that make their own food through photosynthesis (ONLY plants and certain microscopic organisms)

6. Types of Organisms in Ecosystems Cont’d…
consumers: organisms that eats other producers or consumers to get energy (ALL animals)

7. Types of Organisms in Ecosystems Cont’d…
There are four types of consumers:
Type of Consumer
Definition
herbivore
Eats plants
carnivore
Eats other animals
omnivore
Eats both plants and animals
scavenger
Feeds on the remains of another organism

8. Types of Organisms in Ecosystems Cont’d…
decomposer: an organism that eats dead plant and animal matter to get energy (ex. fungi and bacteria)

9. Food Chains and Webs
food chain: shows feeding relations and how energy passes through an ecosystem

10. Food Chains and Webs Cont’d…
food web: shows how energy is passed through two or more interconnecting food chains
used to predict what happens if a species were removed or added to an ecosystem

11. Trophic Levels and Ecological Pyramids
trophic level: shows the position of an organism in a food chain

12. Trophic Levels and Ecological Pyramids Cont’d…
energy pyramid
shows the energy transfer loss and transfer between trophic levels
only 10% of energy is passed from one organism to the next because energy is used by the organism and is lost as heat
less energy available to species in higher levels, therefore, they have smaller populations

13. Trophic Levels and Ecological Pyramids Cont’d…
numbers pyramid: number of individuals in each trophic level
biomass pyramid: shows the total mass of the individuals combined at each trophic level

14. Foldable: Ecological Pyramid
Demonstrate the relationships among ecological components by organizing them into energy pyramids.

15. Learning Goals
We are learning the difference between food chains and webs.
We are learning the different feeding roles in an ecosystem.

16. Homework Finish pyramid activity! Read pages 42-47
Answer questions # 1-8 on page 47