1. Feeding Relationships

2. Energy flows in one direction
from sun or inorganic molecules
to autotrophs
to heterotrophs

3. Food Chains
Series of steps in which organisms transfer energy by eating and being eaten

4. Arrows show the flow of energy

5. Food Chain in an Antarctic Ecosystem

6. Food Webs
Interconnected food chains within an ecosystem

8. Each step of a food web or food chain is a trophic level.
Consumers depend on the trophic level below for their energy.
2nd and higher levels – consumers
1st trophic level – producers

9. Trophic Relationships
4th Level Consumers (top predators)
3rd Level Consumers
2nd Level Consumers
1st Level Consumers (herbivores)
Autotrophs

11. Producers

15. Ecological Pyramids

16. Ecological Pyramids
Show relative amounts of energy or matter within trophic levels of food chains and food webs

17. Energy Pyramids shows amount of available energy at each level
most energy is consumed at each level for biological processes or lost as heat
only about 10% of energy is transferred to next level
0.01%
0.1% 1%
10%
100%

18. 0.01%
0.1% 1%
10%
100%

19. Heat Heat Heat 100% 10% 1% Autotrophs Herbivores Carnivores Consumed

20. Biomass Pyramid
represents available food (organic matter)

21. Pyramids of Numbers
represents the number of individuals at each trophic level

22. Review How does energy flow through an ecosystem?
Draw a food chain with at least 3 consumers.
What do the arrows indicate?
To show all of the feeding relationships in an ecosystems, biologist use a/(an) __ __.
How much energy is transferred from one organism to the other?
What happens to the energy that is not transferred?
What is biomass?
What information is found in a biomass pyramid?
What is represented by a pyramid of numbers?