Energy Flow in a Food Chain/Webs

Energy

• Every living thing needs energy in order to live

• Every time consumers do something (run, jump) they use energy

• Plants get their energy from photosynthesis

• Energy is needed for living beings to grow

The Food Chain • Brainpop - Food Chains

• A food chain shows how living thing gets energy

• Energy is passed from creature to creature

• Food chains begin with plant-life, and end with animal-life.

• Arrows are used to represent energy being passed

Different types of Food Chains • There can be many links in food chains but

not TOO many

• If there are too many links, then the animal at the end would not get enough energy

Food Chain with Decomposers

• Food chains make a full circle!

• Energy is passed from plant to animal to animal to decomposer and back to plant!

Food Web • Is a bunch of food

chains in one

• Several connections may occur between organisms

• Ex: Snake gets energy from frogs and rabbits

Lets see how well you understand what we learned so far:

GAME

http://www.sheppardsoftware.com/content/animals/kidscorner/games/foodchain

game.htm

Food Chain Reaction A change in the size of one population in a food chain will affect other populations. This interdependence of the populations within a food chain helps to maintain the balance of plant and animal populations within a community.

Food Chain Reaction

http://www.ecokids.ca/pub/eco_info/topics/frogs/chain_reaction/play_chainreaction.cfm

http://www.ecokids.ca/pub/eco_info/topics/frogs/chain_reaction/play_chainreaction.cfm

http://puzzling.caret.cam.ac.uk/game.php?game=foodchain

Consumers that eat producers to get energy:

• Are primary consumers = First-Order

A consumer that eats another consumer for energy:

• Is called a secondary consumer= Second-Order

A consumer that eats a consumer that already ate a consumer:

• Is called a tertiary consumer= Third-order

A consumer that eats a consumer that ate a consumer that already ate

a consumer:

• Is called a quaternary consumer = Fourth-Order

Transfer of Energy in a Food Chain

The transfer of energy (arrows)

1. Sun to producer

2. To primary consumer

3. To secondary consumer

4. To tertiary consumer

5. To quaternary consumer

At the bottom of this page! • Make a food web using the following

animals. (write words don’t draw)

• Include the Arrows showing energy.

Name__________________________ Date___________ Period__________ #_____________

Snakes

Rabbits

Mountain Lion

Hawks

Mice

Grass Shrubs

Trees

Decomposers

Seed Eating Birds

Deer First-order heterotrophs

Second-order heterotrophs

Autotrophs

ENERGY PYRAMID

Another way of showing the transfer of energy in an

ecosystem

How is energy being used?

• Some of the energy is being used in the consumer

• Some energy is lost as heat

• Some energy is stored and can pass on to another consumer

How it works… ECO-PYRAMIDS: The concept of a pyramid is useful to describe the energy (trophic) levels of organisms, the amount of biomass, and amount of energy transferred from one trophic level to another. The base of a pyramid is the widest part. Producers are at the base of the eco-pyramid. There are more producers than any type of organism in an ecosystem. 100% of the energy captured from the sun is in the base. There is much more biomass in the base than anywhere else in the pyramid. The second level up a pyramid is smaller than the base. Here is where the primary consumers are placed. There are fewer primary consumers than producers. There is only about 10% of the biomass that is found in the base. Only 10% of the energy captured from the sun by the producers is passed up to this level. The third level up the pyramid is smaller than the second. Here is where the secondary consumers are placed. There is only about 1% of the biomass that is found in the bass (That's 10% of the biomass in the level below it!). This level has only 1% of the energy that is captured from the sun. (That's 10% of the energy in the level below it!) The fourth level is the last level. It is the last level because there is not enough energy left to pass up to another level. This is the level of the tertiary consumer. Only 0.1% of the energy captured by the producers makes it up to this level. Only 0.1% of the biomass in the ecosystem is contained in this level as well.

GENERAL PATTERNS IN THE ECO-PYRAMID: "THE 10% RULE“ - Only 10 % of the energy from a level is passed up to the next level - Only 10 % of the biomass from a level is passed up to the next level There are always fewer individuals in the populations as you go up the pyramid. The higher you go on the pyramid, the less energy is available!

How much energy is lost?

• At each level only 10% of the energy available is passed on.

• 10% Rule Video clip

• Brainpop Energy Pyramid

Trophic Levels: • The trophic level

is the position an organism holds in a food chain or web

1. Primary producer 2. Primary Consumer 3. Secondary

consumer 4. Tertiary Consumer 5. Quaternary

Consumer

10,000 kcal of plants

1,000 Bleak Fish

100 Perch

1 Osprey

10 Northern Pike

Your Turn!

• Use the notes to help you answer all the questions about the relationships in food webs, food chains and food pyramids.

• If you don’t finish it’s HOMEWORK!!!