1.3 Energy and Equilibria

A _________________ feedback loop moves a system to an extreme.

• Positive

• Neutral

• Circular

• Negative

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NGSS.HS-LS1-3

A ________________ feedback loop makes a system more stable.

• Positive

• Neutral

• Negative

• Circular

Tags

NGSS.HS-LS1-3

Which of the following is an example of positive feedback?

• Predator prey

• Human body temperature

• Deforestation

• Toilet flush

Answer explanation

the incorrect answer choices are examples of systems that keep themselves in balance - they involve negative feedback.

Negative feedback amplifies the change in the system and keeps it going in the same direction. Answer true or false.

• true

• false

Tags

NGSS.HS-LS1-3

Which type of feedback is shown in the figure below?

• positive feedback loop

• negative feed back loop

• neutral feed back loop

• tipping point

Answer explanation

This feedback will amplify the change in the system. Once the vegetation cover is removed it will cause more vegetation cover to be removed. So accelerating the change in the system.

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NGSS.HS-ESS2-2

NGSS.HS-ESS3-5

A tipping point is part of a system that kick starts self-perpetuating positive feedback loops that push the systems to a new state of equilibrium. If tipping points are reached in the natural environment, which one of the following could happen?

• Land and seas’ food production capacity could be compromised.

• The climate may become unsuitable for human existence.

• Environmental support services could collapse.

• All of these are possible outcomes of tipping points in the natural environment.

Answer explanation

Are any of these outcomes more significant than the others? or are they all equally significant? Are all of these examples a possible result of reaching a tipping point or just one?

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NGSS.HS-ESS2-2

NGSS.HS-ESS3-5

NGSS.HS-ESS2-4

Polar Ice Caps are melting due to an increase in Earth's temperature. This lowers the albedo of Earth, which in turn increases Earth's temperature. This is an example of what type of feedback?

• Negative

• Neutral

• Positive

• Ecosystem

Which is an example of negative feedback

• loss of vegetation leading to soil erosion leading to further loss of vegetation

• a decline in a large predator population after they have eaten most of their prey population

• melting of permafrost in the tundra due to climatic change leading to further release of methane, causing further change

• unsustainable slash and burn agriculture practices in tropical rainforests.

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NGSS.HS-LS2-6

NGSS.HS-LS4-5

Steady state equilibrium has many small changes over shorter periods of time and the changes occur within limits. Small changes in part of the system will be countered by positive feedback and the system is brought back to the same state as before.

Answer true or false.

• true

• false

Answer explanation

Steady state equilibrium has many small changes over shorter periods of time and the changes occur within limits. Small changes in part of the system will be countered by negative feedback and the system is bought back to the same state as before. Positive feedback loops amplify change they do not counter them.

Tags

NGSS.HS-LS1-3

Which of the following explains why stability varies between ecosystems?

• Climate, limiting factors.

• Biodiversity, trophic complexity.

• Frequency and intensity of disturbances.

• All the responses are correct.

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NGSS.HS-LS2-6

NGSS.HS-LS4-5

NGSS.HS-LS2-2