1. Energy Flow Through an Ecosystem
Food Chains, Food Webs, Energy Pyramids

2. What is the ultimate source of energy on Earth?
The Sun

3. How does the energy from the sun reaches Earth?
What happens to sunlight wave when it gets to Earth?
It is captured by some organisms (mostly plants, but some bacteria and algae too)
Photosynthesis

4. The chemical reaction by which green plants use water and carbon dioxide and light from the sun to make glucose.
ENERGY is stored in glucose; glucose is stored as starch.

5. Organisms that can make glucose during photosynthesis are called AUTOTROPHS or PRODUCERS.

6. Troph = to feed
Auto= self
Autotroph = feeds itself

7. Autotrophs/Producers use most of the energy they make for themselves.

8. The energy that is not used by producers can be passed on to organisms that cannot make their own energy.

9. Organisms that cannot make their own energy are called HETEROTROPHS or CONSUMERS.

10. Consumers that eat producers to get energy:
Are first order or primary consumers
Are herbivores (plant-eaters)

11. Most of the energy the primary consumer gets from the producer is used by the consumer.

12. Some of the energy moves into the atmosphere as heat.

13. Some energy in the primary consumer is not lost to the atmosphere or used by the consumer itself. This energy is available for another consumer.

14. A consumer that eats another consumer for energy:
Is called a secondary or second order consumer
May be a carnivore
May be a predator
May be a scavenger

15. Most of the energy the secondary consumer gets from the primary consumer is used by the secondary consumer.

16. Some of the energy is lost as heat, but some energy is stored and can passed on to another consumer.

17. A consumer that eats a consumer that already ate a consumer:
Is called a third order or tertiary consumer
May be a carnivore
May be a predator
May be a scavenger

18. Consumers that eat producers & other consumers
Are called omnivores
Omnivores eat plants and animals

19. Consumers that eat other consumers that have already died are called scavengers.

20. Decomposers: break down waste and dead organisms and return the raw materials to the environment.
Ex. Bacteria, fungi

21. The transfer of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer can be shown in a FOOD CHAIN.

22. Trophic Level
Each step in a food chain is called a trophic level. Think of it as a feeding level.
1st trophic level: autotrophs/producers
2nd trophic level: primary consumers
3rd trophic level: secondary consumers
4th trophic level: tertiary consumers
5th trophic level: quaternary consumers

23. On your own Draw an example of a food chain Label the trophic levels
Label producers and consumers

24. Another way of showing the transfer of energy in an ecosystem is the ENERGY PYRAMID.

25. Energy pyramids show
That the amount of available energy decreases up the food chain
It takes a large number of producers to support a small number of primary consumers
It takes a large number of primary consumers to support a small number of secondary consumers

26. 3 types of pyramids Energy Pyramid Biomass Pyramid
Biomass: total mass of living matter at each trophic level.

27. Pyramid of Numbers: each level represents the number of individual organisms consumed by the level above it

28. 10% law
Only about 10% of energy is transferred from one level to the next
The other 90% is used by the organism to carry out its life processes or it is lost to the environment

29. Food Webs: Are interconnected food chains
They show the feeding relationships in an ecosystem

30. Acknowledgement
Adapted from