1. SECTION 2 NUTRITION AND ENERGY FLOW
Chapter 2
SECTION 2
NUTRITION AND ENERGY FLOW

2. How Do Organisms Obtain Energy?
Autotroph
Heterotroph

3. Autotrophs
Organisms that use energy from the sun or chemicals to make their food; also called producers

4. Heterotrophs
Organisms that depend on autotrophs for nutrients and energy; also called consumers.

5. Types of Heterotrophs Carnivores Herbivores Scavengers Omnivores
Decomposers

6. Carnivores
Only eat meat

7. Herbivores
Only eat plants.

8. Scavengers
Feed on carrion, refuse, and similar dead organisms

9. Spotted Hyena chasing away a vulture.

10. Omnivores
Eat a variety of plants and animals

11. Decomposer
Break down complex compounds of dead and decaying organisms into small, absorbable molecules; these are fungi or bacteria.

12. How Does Matter and Energy Flow in Ecosystems?

13. Food Chain
A model that shows how matter and energy move through an ecosystem.
algae  fish  bird
Arrows show direction of energy

14. There are usually no more than 5 links because the amount of energy has been lost.

15. Trophic Levels A feeding step in a food chain.
Many different species occupy each trophic level in an ecosystem.
Many organisms feed from several different trophic levels.

18. Food Web
Food webs express all of the possible feeding relationships at each trophic level in a community.

19. Ecological Pyramids Show energy conversion in a ecosystem.
Pyramid of energy - energy decreases at each higher trophic level.
Pyramid of numbers - population size decreases or increases at each higher trophic level.

20. Pyramid of Energy
The total transfer of energy from one trophic level to the next is 10%. What happens to the rest of the energy?

21. Pyramid of Numbers
Can you think of an example where the pop. Size will increase at each higher trophic level?