Unit 5 - Energy in Ecosystems

Autotroph

an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.

Heterotroph

an organism deriving its nutritional requirements from complex organic substances.

Carbon-Oxygen Cycle

Plants use carbon dioxide to make the food that most living things need to live.

photosynthesis

the process by which plants and plantlike organisms make food.

chlorophyll

A green pigment found in the chloroplasts of plants, algae, and some bacteria

chloroplasts

A structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food.

stoma

tiny holes where oxygen is released from a plant

producer

An organism that can make its own food.

Phytoplankton

Microscopic, free-floating, autotrophic organisms that function as producers in aquatic ecosystems (plantlike)

consumer

An organism that obtains energy by feeding on other organisms

herbivore

A consumer that eats only plants.

Carnivore

A consumer that eats only animals.

Omnivore

A consumer that eats both plants and animals

predator

An animal that hunts other animals for food

prey

Animal hunted or caught for food

food chain

the transfer of food energy from one organism to the next in an ecological community

food web

when food chains overlap

energy pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food chain

10%

The amount of energy transferred from one level to another.

90%

Amount of energy received from the lower level is used for life processes

scavenger

A carnivore that feeds on the bodies of dead organisms

Decomposer

organism that breaks down and obtains energy from dead organic matter and the final link to the food chain

Enzymes

used by decomposers to break down dead matter, releasing nutrients that enrich the soil

first level consumers

Herbivores.They get energy from the plants they eat.

Second level consumer

Consumers that eat first level consumers. Carnivores and Omnivores.

Third level consumer

organisms that eat secondary consumers; also called tertiary consumers. Carnivore, omnivore or Scavenger.