Question

1.Which of the following would act as a negative feedback loop?

Select one:

a. Increased evaporation of water, which results in more clouds.

b. Higher temperatures, which increase release of dissolved carbon dioxide from the oceans.

c. Increased absorption of carbon dioxide by the oceans, which results in ocean acidification.

d. Melting of polar ice, which alters ocean circulation patterns.

2.The sawtooth pattern of increasing and decreasing carbon dioxide concentrations observed by Charles Keeling at Mauna Loa Observatory was a result of:

Select one:

a. increased burning of fossil fuels during the winter in the northern hemisphere.

b. seasonal changes in photosynthesis and respiration, particularly in northern hemisphere ecosystems.

c. the Kyoto Treaty and other global efforts to limit carbon dioxide emissions.

d. errors caused by monitoring instruments.

Answer 1

1. Option A is correct
A negative feedback loop is characterized by inhibition of the pathway by the end product of the pathway.
Increased evaporation of water results in more clouds formation.
However, cloud formation, in turn, exhibits a negative feedback effect on the evaporation of water.

2. Option B is correct
The CO₂ concentrations exhibit cyclic changes during different seasons.
During the summer, the CO₂ levels reduce.
During winter, the CO₂ levels increase.
This is due to the fact that winter is characterized by reduced photosynthesis and sustained respiration.