7th Biofeedback Loops

Whch of the following is an example of a positive feedback loop?

• As glaciers melt, there is less white surface to reflect heat, which causes more melting

• As plants grow their litter creates more soil humus, which in turn makes it more hospitable for more plants.

• "Violence breeds more violence" - or, a violent act by one group causes their enemy to retaliate with more violence

• All of the above

Tags

NGSS.HS-ESS2-2

NGSS.HS-LS2-6

Negative feedback is called negative because ____.

• it counteracts disturbance

• it causes degradation of an ecosystem

• it has a destabilizing effect

• it has no effect on system stability

Tags

NGSS.HS-LS1-3

The strength of a feedback loop is ___.

• The sum of the positive link strengths in the loop

• The sum of all the link strengths in the loop

• The product of all the link strengths in the loop

• The sum of the positive link strengths divided by the sum of the negative link strengths in the loop.

If you have a feedback loop with three strong negative links, and one of those links turns into a very weak positive link, what will the resulting feedback be?

• strong positive feedback

• strong negative feedback

• weak positive feedback

• weak negative feedback

• no feedback

How many feedback loops are possible in a food web of 20 species?

• up to 20

• around 80

• hundreds

• thousands

Tags

NGSS.HS-LS2-6

How do all the feedbacks togethers in an ecosystem create harmony? One important mechanism is:

• the feedbacks become synchronized

• positive feedbacks counteract destabilizing negative feedbacks

• many populations interacting causes break-up of the chains of the short feedback loops

• destabilizing positive feedbacks are counteracted negative feedbacks

Tags

NGSS.HS-LS2-6

Scenario: As ice sheets melt, this could increase cloudiness with more water vapor in the atmosphere. Because clouds reflect 1/3 of incoming solar radiation, there would be less heat absorption on Earth's surface.

• Positve Feedback

• Negative Feedback

Tags

NGSS.HS-ESS2-2

NGSS.HS-ESS2-4

In the Arctic tundra, permafrost melt will trigger methane release in the atmosphere. Because methane is a more potent greenhouse gas than CO2.

• positive feedback

• negative feedback

Tags

NGSS.HS-ESS2-2

NGSS.HS-ESS2-4

NGSS.HS-ESS3-5

Your body heats up on a hot day. The sensors in your skin detect the rising temperature. As a result you start to sweat and blood flows to the skin capillaries to lose heat. Your body loses heat.

• positive feedback

• negative feedback

Tags

NGSS.HS-LS1-3