Section 13-3 & 13-4Section 13-3 & 13-4“Energy “Energy

& Food Chains ”& Food Chains ”

Write everything Write everything that isthat is underlinedunderlined

13.3 Energy in Ecosystems / 13.4 Food Chains

Section 13.3Section 13.3 KEY CONCEPT KEY CONCEPT: : Life in an ecosystem requires a Life in an ecosystem requires a source of energy.source of energy.

13.3 Energy in Ecosystems / 13.4 Food Chains

I.I. Energy in an EcosystemEnergy in an Ecosystem1. Producers provide energy for 1. Producers provide energy for other organisms in an ecosystemother organisms in an ecosystem..

2.2. Producers get their energy from non-Producers get their energy from non-living resourcesliving resources (like the sun).(like the sun).

3.3. Producers are also called autotrophs Producers are also called autotrophs because they make their own foodbecause they make their own food (“auto” means “self”).(“auto” means “self”).

13.3 Energy in Ecosystems / 13.4 Food Chains

4.4. Almost all producers obtain energy from Almost all producers obtain energy from sunlight.sunlight.

a.a. Photosynthesis in Photosynthesis in most producers uses most producers uses sunlight as an sunlight as an energy source. energy source. (plants do this)(plants do this)

b.b. ChemosynthesisChemosynthesis in in prokaryote prokaryote producers uses producers uses chemicals as an chemicals as an energy source.energy source.

carbon dioxide + water +carbon dioxide + water +hydrogen sulfide + hydrogen sulfide + oxygenoxygen

sugar + sulfuric acidsugar + sulfuric acid

13.3 Energy in Ecosystems / 13.4 Food Chains

5.5. Consumers are organisms that get their Consumers are organisms that get their energy by eating other living things.energy by eating other living things. (or dead things that used to be alive)(or dead things that used to be alive)

6.6. Consumers are also called heterotrophsConsumers are also called heterotrophs because because they feed off of different thingsthey feed off of different things. . (“hetero” means “different)(“hetero” means “different)

13.3 Energy in Ecosystems / 13.4 Food Chains

Section 13.4Section 13.4 KEY CONCEPT: KEY CONCEPT: Food chains and food webs model Food chains and food webs model the flow of energy in an ecosystem.the flow of energy in an ecosystem.

13.3 Energy in Ecosystems / 13.4 Food Chains

I.I. Food ChainsFood Chains1. A food chain is a model that shows a 1. A food chain is a model that shows a sequence of feeding relationships.sequence of feeding relationships.

2.2. A food chain follows the connection between A food chain follows the connection between one producer and a single chain of consumers one producer and a single chain of consumers within an ecosystem.within an ecosystem.

DESERT COTTONTAILGRAMA GRASS HARRIS’S HAWK

13.3 Energy in Ecosystems / 13.4 Food Chains

II.II. Consumers are not all alike.Consumers are not all alike.

1.1. Herbivores eatHerbivores eat only only plantsplants..

2.2. Carnivores eatCarnivores eat only only animalsanimals..

3.3. Omnivores eatOmnivores eat both both plants and animalsplants and animals..

4.4. Detritivores eat dead organic matterDetritivores eat dead organic matter..

5.5. DecomposersDecomposers are detritivores that break are detritivores that break down organic matter into simpler down organic matter into simpler compoundscompounds..

carnivore decomposer

13.3 Energy in Ecosystems / 13.4 Food Chains

6.6. Specialists are consumersSpecialists are consumers that that primarily primarily eat one specific organismeat one specific organism or a very small number of or a very small number of organismsorganisms..

7.7. GeneralistsGeneralists are consumers that are consumers that have a varying diethave a varying diet..

13.3 Energy in Ecosystems / 13.4 Food Chains

III.III. Trophic levels are the nourishment levels in a Trophic levels are the nourishment levels in a food chain.food chain.

– Primary consumersPrimary consumers are are herbivores that eat herbivores that eat producers. producers.

– Secondary consumersSecondary consumers are are carnivores that carnivores that eat herbivoreseat herbivores..

– Tertiary consumersTertiary consumers are are carnivores that eat carnivores that eat secondary consumerssecondary consumers..

– OmnivoresOmnivores, such as humans that eat both , such as humans that eat both plants and animals, plants and animals, may be listed at different may be listed at different trophic levels in different food chainstrophic levels in different food chains..

13.3 Energy in Ecosystems / 13.4 Food Chains

5.5. Food Chains: Notice the arrow points Food Chains: Notice the arrow points toward the animal that is doing the eating toward the animal that is doing the eating (the eater)(the eater)

The mouse is going into the snakes mouth

The snake is going into the fox’s mouth

13.3 Energy in Ecosystems / 13.4 Food Chains

6.6.A food web shows a complex A food web shows a complex network of feeding relationships.network of feeding relationships.

a.a. An organism may have multiple feeding An organism may have multiple feeding relationships in an ecosystem.relationships in an ecosystem.

b.b. A food web emphasizes complicated A food web emphasizes complicated feeding relationships and energy flow in an feeding relationships and energy flow in an ecosystem.ecosystem.

13.3 Energy in Ecosystems / 13.4 Food Chains

Food WEB – notice all the different arrowsFood WEB – notice all the different arrows

13.3 Energy in Ecosystems / 13.4 Food Chains

Review Questions 13.2 & 13.3Review Questions 13.2 & 13.3

1.1. What does all life in an ecosystem require?What does all life in an ecosystem require?

2.2. What is another name for producer?What is another name for producer?

3.3. What are consumers also called?What are consumers also called?

4.4. What is a food chain and food web?What is a food chain and food web?

5.5. What do herbivores, carnivores, omnivores, What do herbivores, carnivores, omnivores, detritivores and decomposers eat?detritivores and decomposers eat?

6.6. Define Primary, secondary and teriary consumers.Define Primary, secondary and teriary consumers.