Energy Flow

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

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

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

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

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

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

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