Energy Flow: FOOD CHAINS

& WEBSEQ: Explain the difference between a food web and a food chain.

sun eclipse with palmthe ultimate energy source

Energy FlowHow does the sun’s energy

enter the biological world?What is photosynthesis?

Energy Flow

The sun’s energy flows into organisms that can change the sunlight into food then into organisms that eat them.

This flow is:

sunlight producer consumer 1 consumer 2

PRODUCERS

Organisms that can produce their own food (glucose) through photosynthesis. AKA - Autotrophs

Ex. Plants, algae and some bacteria

sunlight producer consumer 1 consumer 2

CONSUMERS

Organisms that have to eat other organisms to obtain energy. AKA - Heterotrophs

Examples: deer, rabbits, cows, mice, lions, humans, hawks, snakes

sunlight producer consumer 1 consumer 2

HERBIVORES

Organisms that eat plants

Primary ConsumersEx. Cows, caterpillars, bunnies

sunlight producer consumer 1 consumer 2

CARNIVORES

Organisms that eat meat (other animals/consumers)

Secondary ConsumersEx. tigers, wolves, snakes, hawks

sunlight producer consumer 1 consumer 2

TOP CARNIVORESTop-level carnivores eat

secondary consumers; usually nothing feeds on them

Tertiary ConsumerEx. killer whale eating a sea

lion or hawk eating a snake.

sunlight producer consumer 1 consumer 2

consumer 3

OMNIVORESConsumers that eat both plants

and animals

Primary and Secondary Consumers

Ex. bears and humans

Where do allthe dead things go?

They are eaten. YUMMMM!

They decay. SMELLY!

What’s the difference?Is it just a matter of taste?

decomposerdetr

itivore

Detritivore vs Decomposers

Detritivores and decomposers both feed on the remains of dead plants and animals and other dead matter (detritus)

They rely on dead tissues for nutrients.

detritiv

oredeco

mposer

Detritivore vs Decomposers

Detritivores eat the remains of dead plants and animals

Decomposers breakdown (decay) organic matter and feed on it

Crabs, mites, earthworms, snails

Bacteria & fungi

Detritivores and Decomposers

What is a scavenger?

A scavengers is a type of detritivore that feeds on carrion (dead animal remains). Ex. vultures, sharks,

maggots, hyenas

Detritivores and Decomposers

Decomposers are often called the environmental “recyclers”because….

They decompose excrement, dead bodies and leaf litter, returning

nutrients to the physical environment. consumer 3

sunlight producer consumer 1 consumer 2

decomposer

Energy Flow

The series of steps in which organisms transfer energy by eating and being eaten is called a

Food Chain

sunlight producer consumer 1 consumer 2

Food Chains & Food WebsThe steps in the transfer of energy

from organism to organism in feeding relationships are called

Trophic Levels.How does a food chain describe

this path of energy? (arrows)

producer consumer 1 consumer 2 consumer 3

Food Chains & Food Webs

Name the number of the trophic levels in the food chain below.

How do the trophic level numbers correspond with the “eating terms”?

producer consumer 1 consumer 2 consumer 3

TrophicLevel 1 2 3 4

Food Chains & Food WebsSome energy is lost from one level to

the next level due to heat energy or metabolism.

Only 10% of the energy from one level is passed to the next level!!

No trophic level can contain more energy than the level before.

producer consumer 1 consumer 2 consumer 3

Food Chains & Food WebsWhat vital “recycler” is not shown

in this food chain?Upon which organism(s) would it

feed?

producer consumer 1 consumer 2 consumer 3

decomposer

Food Chains & Food WebsIf all of the snakes in this chain died,

what would happen to the hawk?To the decomposers?

producer consumer 1 consumer 2 consumer 3

decomposer

Food Chains & Food WebsMost organisms feed on more than

one trophic level and feed on several different species at each trophic level. This is a food web.

Arctic Food Web

http://www.arctic.noaa.gov/essay_krembsdeming.html

Rangeland Prairie Food Web