Trophic Levels, Food Chains, and Food Webs Review

ECOLOGY REVIEW

Energy Flow In Ecosystems

How Energy Flows

• Energy flows through an ecosystems in one direction

• Starting with the sun or chemical compounds

• Then to autotrophs(producers)

• Then to various heterotrophs(consumers)

Multiple Select

Select all of the terms that describe an autotroph

• organisms that produce their own food

• producers

• organisms that consume what they eat

• consumers

Multiple Choice

Where does the all of the energy available in an ecosystem originally come from?

• autotrophs

• heterotrophs

• the sun

Food Chains

• Food chains show how matter and energy move through ecosystems in a series of steps

• Each step shows which organisms transfer energy by eating and being eaten

• The arrows show who is being transferred the energy (who is doing the eating)

Food Chains

• Each organisms in a food chain represents a feeding step, or trophic level, in the transfer of matter and energy

Multiple Choice

Food chains show you what?

• What organisms like to do

• How organisms grow and reproduce

• How matter and energy move through ecosystems

Multiple Choice

What do the arrows show in a food chain?

• They point to the smallest animals.

• They point to the animal that tastes the best.

• They point to just the producers.

• They point in the direction that energy is flowing.

Food Webs

Models that show all possible feeding relationships at each trophic level in a community; links all food chains in an ecosystem together.

Hotspot

Select all of the organisms in the food chain from Phytoplankton to Tundra Swans

Types of Consumers in a Food Web

• Herbivores- eat only plants

• Carnivores- eat only animals

• Omnivores- eat plants and animals

• Detritivores- eat detritus, or deadorganic matter

• Decomposers- break down organic matter into simpler compounds; important to the stability of an ecosystem because they return vital nutrients back into the environment

Hotspot

Select any animal that is just a carnivore

Hotspot

Select any animal that is just an herbivores

Hotspot

Select any animal that is just an omnivore

Drag and Drop

If there was an increase in the elf owl population size there would be an ​

Placeholder

in the population sizes of the ​

Placeholder

, ​

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, and the ​ red harvester ant.

Drag these tiles and drop them in the correct blank above

decrease

mantid

pallid-winged grasshopper

increase

wood rat

grasshopper mouse

gila woodpecker

Multiple Select

Select the organism(s) that compete with the Stoat for food.

• Collard Lemming

• Artctic Fox

• Skua

• Snowy Owl

• Ptarmigan

Trophic Levels

• Notice that producers are always on the bottom of the energy pyramid

• We call consumers on the first level Primary Consumers

• We call consumers on the next level Secondary Consumers

• We call consumers on the next level Tertiary Consumers

The 10% rule is a concept that explains the flow of energy through an ecosystem.

The 10% rule states that only about 10% of the energy available at one trophic level is transferred to the next trophic level. This means that if a plant produces 1,000 calories of energy, only about 100 calories of that energy will be transferred to the herbivore that eats the plant. Then, if a predator eats the herbivore, only about 10 calories of energy will be transferred to the predator.

The 10% Rule

Multiple Choice

Which level of the energy pyramid has the most stored energy?

• Producers

• Primary Consumer

• Secondary Consumer

• Tertiary Consumer

To calculate 10% of a number, you need to divide the number by 10. Here's an example:

Let's say you want to find 10% of 50. To do this, you would divide 50 by 10, like this:

50 ÷ 10 = 5

So, 10% of 50 is 5.

Another way to think about it is to move the decimal point one place to the left. For example, if you want to find 10% of 70, you would move the decimal point one place to the left to get 7.0, which is the same as 7.

That's all there is to it! Just divide the number by 10 or move the decimal point one place to the left to find 10% of a number.

The 10% Rule Contiued

Math Response

If there's 20,000 kcal on the producer level of this trophic pyramid, how many kcal will be passed on to the primary consumers?

Type answer here

Correct Answer: 2000

Deg^°

Rad

Math Response

Assuming that there's 20,000 kcal on the producer level of this trophic pyramid, how many kcal will be passed on to the quaternary consumers?

Type answer here

Correct Answer: 2

Deg^°

Rad