1. Food Chains and
Food Webs

2. Autotrophs/Producers
A groups of organisms that can use the energy in sunlight to convert water and carbon dioxide into Glucose (food)
Autotrophs are also called Producers because they produce all of the food that heterotrophs use
Without autotrophs, there would be no life on this planet
Ex. Plants and Algae

3. Autotrophs/Producers

4. Heterotrophs/Consumers
Organisms that do not make their own food
Another term for Heterotroph is consumer because they consume other organisms in order to live
Ex. Rabbits, Deer, Mushrooms

5. Heterotrophs/Consumers

6. Transfer of Energy
When a zebra eats the grass, it does not obtain all of the energy the grass has (much of it is lost)
When a lion eats a zebra, it does not get all of the energy from the zebra (much of it is lost)
Inefficient EVERGY TRANSFER!

7. Food Chains
The energy flow from one trophic level to the other is know as a food chain
A food chain is simple and direct
It involves organisms at separate trophic levels
Primary Consumers – eat autotrophs (producers)
Secondary Consumers – eat the primary consumers
Tertiary Consumers – eat the secondary consumers
Decomposers – bacteria and fungi that break down dead organisms and recycle the material back into the environment

8. Food Chain

9. Food Web

10. Food Web
Notice that the direction the arrow points  the arrow points in the direction of the energy transfer
The arrow indicates “is eaten by”

11. Interdependence in Food Webs
The linkages in a food web illustrate the feeding pathways, such as where heterotrophs obtain organic matter by feeding on autotrophs and other heterotrophs.
The food web is an illustration of the various feeding methods that links an ecosystem into a unified system of exchange.
If “something happens” to one member of the food web, it will affect then entire ecosystem.

12. Niches in Food Webs Niche: the role the organism has in an ecosystem
Niches exist in food webs; if more than one species occupies the same niche in a food web, they will eventually need to compete to resources.

13. The Hawk eats the Hare. TRUE/FALSE

14. The Owl eats the Hawk. TRUE/FALSE

15. The fox eats the mouse, chipmunk, and frog. TRUE/FALSE

16. The weasel is eaten by the fox and the mouse. TRUE/FALSE

17. The frog eats the dragonfly. TRUE/FALSE