AIM: How is energy transferred in an ecosystem?

DN: Explain the difference between a primary consumer, secondary consumer and tertiary consumer.

HW: Article

How do producers get their energy?

The primary source of energy for living things

is the____.

____________capture this energy through the

process of _________________

sunAutotrophs

photosynthesis

How do the cows we eat get their energy?

Primary consumers get their energy from the producers they eat

How is energy transferred in a community?

• Energy is transferred by consuming other organisms

In which direction is the energy moving? Why?

Shows the transfer of energy from one organism to another in a community

Food Chains

In which direction is energy flowing?

• All Food chains begin with producers!!!!

• All organisms are consumed by decomposers (feed at all trophic levels)

Do most organisms eat just one type of food?

Food Webs

Many food chains representing the feeding relationship among the organisms in an ecosystem

• Food webs link organisms in an ecosystem

• Changes in the population of one organism can affect many other organisms

In Antarctica• Primary producer is microscopic algae• Primary consumer are small shrimp-like

crustaceans called krill• Fish, penguins, seals, baleen whales all feed on

krill

Commercial whaling decreased the number of baleen whales. How does that affect the other organisms in this ecosystem?

The number of fish, penguins and seals will increase. Why?

There is more food available for them since there is now less competition (baleen whale population

decreased)

Which ecosystem would be more stable? Why?

A food web with more diversity is more stable because it can better withstand the loss of

one species.

What happened to the bald eagles?

DDT

Biological MagnificationThe increasing concentration of a pollutant

in organisms at higher trophic (Feeding) levels in a food web

• Biomagnification video clip

Energy Pyramid

Producers

1’ Consumers

2’ Consumers

3’ Consumers

En

ergy

Flo

w

Sun’s Energy in an Ecosystem

• Some of the energy is used by each organism and some of it is lost as heat energy to the environment

Why is there so little energy at the top of the pyramid?

• Most of the energy from the sun has been used or lost by organism in the lower levels

• Only about 10% of the energy available at each level is transferred to the NEXT level.

100%10%

1%

Pyramid of NumbersShows the relativenumber of individualorganisms at eachtrophic level.

Biomass PyramidRepresents the amount ofliving organic matter at each trophic level. Typically, thegreatest biomass is at the base of the pyramid.

Energy PyramidShows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat.

Section 3-2 Ecological pyramids

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