Interdependence of Organisms

It is the year 2525. Humans have polluted all bodies of water on Earth. As a result, almost all previously known species of plant, animal, and other life have become extinct. Through natural selection, genetic engineering, and selective breeding programs, a portion of the Earth has been successfully repopulated. The organisms on the chart at your table are the only that remain.

Your Task… Create a Food Web for the organisms

listed on the worksheet

Use the pictures in the envelope, the whiteboard, and markers at your table to build the web.

Food Web Checkpoint… What direction should the arrows point in your

food web?

What do the arrows represent?

Make any necessary corrections to your food web then check your web against the key!

Why might I have used the word transfer

here?

Check your web - Look at the key your teacher passes out to

see if your web is correct

Energy Flow Checkpoint… What is the source of all energy in the food

web? Draw this in to your food web.

Identify which organisms in your food web are autotrophs and heterotrophs.

Energy Flow Checkpoint… What cellular process do the autotrophs

use to capture energy from the environment?

What cellular process do the heterotrophs and autotrophs use to release stored chemical energy from their food?

A food web is shown above. If the rabbit population increases, which of the following is most likely to happen soon afterward?

A The deer population will increase.B The plant population will decrease.C Different birds will move into the area.D The insect population will be eliminated.

Practice Question:

The diagram above is intended to show relationships in an ecosystem. What do the arrows represent?

A The direction of population migration B Differences in dietary habitsC Progressively smaller organismsD The direction of energy flow

Practice Question:

Your Next Task…

• Create a Food Pyramid with the food chain provided

Big-Mouthed Pelican

Giant Aqua-spidersPentasquidAqua-wheat

Ecological Pyramid Checkpoint… What might each level of the ecological

pyramid represent?

Why does a pyramid best represent these?

Energy Checkpoint… What is the source of energy for your

pyramid and where does this energy enter into the pyramid? Draw it on your pyramid!

Circle the organism responsible for trapping this energy.

Energy Checkpoint… Put a star on the trophic level has the

largest amount of available energy?

Why do you think the energy decreases as you go up each trophic level?

Where does the lost energy go? What form does it take?

Rule of 10% 90% is used in life

processes and released as heat

• Only 10% of each organism’s energy can move to the next level trophic level

Let’s Practice… 10,000 Kcal of energy is available on the

1st trophic level…write this on your pyramid!

Use the rule of 10% to figure the energy available at the 3rd trophic level.

Quick Review…Ecological Pyramids

1. Energy Pyramid: Represents energy flow through food chain

Pyramid of Numbers Create a pyramid of numbers for your food

chain using the following data:

Organism Numbers in each trophic level

Aquawheat 300

Pentasquid 10,000

Giant Aqua Spiders 8,000

Big mouthed pelican 250

Pyramid of Biomass Create a biomass pyramid for your food

chain using the following data: Hint: calculate how many grams are in each

trophic level.Organism Numbers in each

trophic levelMass per individual organism in grams

Aquawheat 300 100 g

Pentasquid 10,000 2 g

Giant Aqua Spiders 8,000 5 g

Big mouthed pelican 250 300 g

Which diagram best shows how the amount of stored energy changes going up a food chain?

a. c.

b. d.

Energy pyramid

There is a certain amount of energy in each trophic level. Sketch a bar graph of the relative energy content in each level.

I wonder? Pentasquid are very sensitive to the water

temperature in the ocean. If the water gets too warm they don’t reproduce as often. What would happen to the organisms in the food chain if temperatures were to rise?