Ecology EOC Review

EOC Review - Day 1

This review is self-paced, but we will go through it together in class.

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Please make sure you finish the questions at the end of the review and the handout.

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The handout counts as your subjective final. The review will count towards minor grades.​

Mutualism

Both species benefit.

Commensalism

One species benefits, the other is neither harmed nor helped.

Parasitism

One species benefits, the other is harmed but not killed.

Predation

One species kills and eats another.

Competition

Two species compete for the same food source.

Multiple Choice

Grizzly bears and timber wolves both hunt deer in Yellowstone National Park. What sort of relationship do the bears have with the wolves?

• Commensalism

• Competition

• Mutualism

• Predation

Multiple Choice

Which accurately describes the relationships between the sunfish and the other species with which it interacts?

• Seabirds: Mutualism

  Jellyfish: Predation

  Copepods: Parasitism

• Seabirds: Parasitism

  Jellyfish: Commensalism

  Copepods: Predatiion

• Seabirds: Predation

  Jellyfish: Mutualism

  Copepods: Commensalism

• Seabirds: Commensalism

  Jellyfish: Parasitism

  Copepods: Mutualism

Decomposers

Decomposers break down dead matter and return the nutrients to the soil.

Each levels in an ecosystem is a trophic level.

Trophic levels include: producers, primary consumers, secondary consumers, and tertirary consumers.​

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​In any food web, the flow of energy starts with the sun.

Energy flows from the Sun to the producers. (Plants)

Energy flows from the producers to the primary consumers. (Herbivores)

Energy flows from the primary consumers to the secondary consumers. (Carnivores)

And energy flows from the secondary consumers to the tertiary consumers. (Top Carnivores)

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Multiple Choice

Based on this food web, which organism occupies multiple trophic levels?

• Canada goose

• Eastern cottontail

• Loggerhead sea turtle

• Sand dollar

Trophic Pyramid

The most energy is always found at the base of the pyramid.

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The least energy is found at the top.

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At each level, only 10% of the energy is transferred up.​

The rest of the energy is lost as heat.​

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Multiple Choice

If 10,000 kilocalories are available to the producers (grass), how many kilocalories will be available to the tertiary consumers (hawks)?

(Hint: as you go up each trophic level, divide by 10).

• 10,000

• 1,000

• 100

• 10

Multiple Choice

If 10,000 kilocalories are available to the producers (grass), how many kilocalories will be available to the secondary consumers (snakes)?

(Hint: as you go up each trophic level, divide by 10).

• 10,000

• 1,000

• 100

• 10

Multiple Choice

If 10,000 kilocalories are available to the producers (grass), how many kilocalories will be available to the primary consumers (rabbits)?

(Hint: as you go up each trophic level, divide by 10).

• 10,000

• 1,000

• 100

• 10

Nitrogen Cycle

Bacteria 'fix' nitrogen (bring it in from the air).

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The bacteria convert the nitrogen to a form that plants can use.

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Plants bring nitrogen in through their roots.

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Nitrogen Cycle

Animals eat the plants.

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When animals excrete waste, nitrogen returns to the soil or the atmosphere.

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Humans can impact the nitrogen cycle by ​overfertilizing crops, burning fossil fuels, and deforestation.

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Carbon Cycle

Carbon is part of all biomolecules.

All life on Earth goes through an endless carbon cycle.

There are four steps to the carbon cycle:

1. Carbon enters the atmosphere as CO2.

2. CO2 is absorbed through photosynthesis done by producers (plants).

Carbon Cycle

3. Animals consume plants, thereby taking in their carbon.

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4. When animals and plants die, their bodies decompose and their carbon is reabsorbed back into the atmosphere.

Carbon Cycle

​Because plants take in and store carbon dioxide when they do photosynthesis, carbon is stored in forests and other places of high vegetation.

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These places are called carbon reservoirs.​

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Carbon Cycle

When humans cut down or burn forests, they are putting more carbon dioxide into the atmosphere.​

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Burning fossil fuels also increases CO2 levels.

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How could humans reduce the CO2 in the atmosphere?​

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How are microorganisms important in maintaining the ecosystem?

Bacteria are essential to both the carbon and the nitrogen cycles.

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Carbon cycle: many decomposers are bacteria.

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Nitrogen cycle: Nitrogen-fixing bacteria.​

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Succession

The gradual, sequential growth of a community in an area.

Pioneer Species

The first species to colonize an area.

Primary Succession

Succession in an area that has not supported life previously.

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Starts with bare rocks. Lichens are the pioneer species because they release acid which breaks rocks down into soil.

Secondary Succession

Succession that follows disruption of an existing community.

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Because there is already a base of soil, pioneer species will be grasses / flowers.

Climax Community

A stable community including mature trees and tertiary consumers.

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This is when an ecosystem has the most species diversity.

Multiple Choice

What type of succession would you expect to see after a forest fire?

• Primary Succession

• Secondary Succession

• Tertiary Succession

• Basal Succession

Multiple Choice

Bees pollinate plants as they move from flower to flower gathering nectar.

How would you classify this relationship?

• Commensalism

• Competition

• Mutualism

• Parasitism

Multiple Choice

Fleas live on the skin of dogs and obtain nutrients from the dogs' blood.

How would you classify this relationship?

• Commensalism

• Competition

• Mutualism

• Parasitism

Multiple Choice

Birds often make nests for themselves in trees. The trees are neither harmed nor helped by the birds.

How would you classify this relationship?

• Commensalism

• Competition

• Mutualism

• Parasitism

Multiple Choice

Please click on the image to zoom in.

• F

• G

• H

• J

Multiple Choice

Please click on the image to zoom in.

• A

• B

• C

• D

Multiple Choice

Please click on the image to zoom in.

• F

• G

• H

• J

Multiple Choice

Please click on the image to zoom in.

• A

• B

• C

• D

Multiple Choice

A new island arises from the ocean due to volcanic eruptions.

This island is bare rock. What kind of pioneer species would you expect to find on this island?

• Lichens

• Grasses

• Shrubs

• Consumers

Multiple Choice

Please click on the image to enlarge it.

• A

• B

• C

• D

Multiple Choice

Please click on the image to enlarge it.

• A

• B

• C

• D