1. Energy Flow

2. I. How Organisms Obtain Energy
1. Autotrophs = use energy from the sun or chemicals to make their own nutrients
plants
some unicellular organisms

3. 2. Heterotrophs - organisms that cannot make their own food
feed on other heterotrophs, or autotrophs

4. A. Types of Heterotrophs
herbivores = eat plants
carnivores = eat other animals
scavengers = animals that feed on organisms that are already dead
black vultures (detritivore)
omnivores = eat both animal and plants
decomposers = break down and absorb nutrients from dead organisms
fungi and bacteria

5. II. Matter and Energy Flow in Ecosystem
A. Food Chain - a simple model that shows how matter and energy move through an ecosystem

6. 1. Trophic Level - a feeding step
2. Only 10% of calories are passed from organism to organism.

7. B. Food Web Food Web - interconnecting food chains
shows how organisms depend on other organisms for food

8. C. Food Pyramid
Food Pyramid - largest amount of energy on bottom