Chapter 18Section 3Energy Transfer

Think- Pair-ShareIf some of the resources in a habitat are destroyed, which would be more likely to survive, a generalist species or a specialist species? Why?

Energy Flow How do we receive our nutrients and

energy? From what we eat Food Metabolizes and energy is transferred As energy flows through and ecosystem is

moves from Producers to Consumers. Trophic Level- a way to organize the path

at which energy flows through and ecosystem.

Trophic Level It indicates an

organisms position in a sequence of energy transfer.

Organized by the organisms eating behaviors.

Trophic Level

Food Chain Single pathway of

feeding relationships among organisms in an ecosystem that results in energy transfer.

Feeding relationships are normally too complex to be represented in a single chain.

Food Chains

Food Web Interlinked or interrelated food

chains.

Energy Transfer The amount of energy stored as organic

material in each trophic level in an ecosystem.

What is organic material? Matter composed of organic

compounds that has come from the remains of once-living organisms such as plants and animals and their waste products in the environment.

Energy Transfer Pyramid shape

represents the low percentage of energy transferred from one level to the next.

Average 10% of the total energy consumed in one level is passed on to the next level.

Energy Transfer Why is the energy % transfer so low? Some escape being eaten Die and become food for decomposers Even if eaten the consumer may not be

able to breakdown the molecules into useful energy.

Ex: Lion eats the hoofs of antlers its prey Energy is lost in the bodies process to

metabolize the food.

Quiz What is the organic material in an

ecosystem called? Biomass What is an organism called that eats both

producers and consumers? Omnivores How much of the total energy is

transferred from one trophic level to the next?

About 10%

Question and Answer Time Do you know why there are only a few trophic

levels? Because there is a low rate of energy transfer

between trophic levels There would not be enough energy to support

additional trophic levels Are there more organisms in the lower trophic

level or the highest trophic level? Lower trophic levels contain more energy Higher trophic levels contains less energy not

being able to provide enough energy to support more organisms.

Questions and Answer Time Explain why food chains and food webs are

more of a transfer of energy than just what eats what?

How does a food chain differ from a food web? Explain why food chains do not exceed three

or four levels? How do producers and consumers obtain

energy? Explain why the same area can support a

greater number of herbivores than carnivores? Describe the probable effects of an ecosystem

if all the plants were to die. What if all the decomposers were to die?