Name:________________________________
Biology 420: Global Change
Midterm Exam
Useful Information:
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1. Consider the following graph and answer the questions that follow:
a. Name the researcher responsible for this graph (1 points):
b. There are two main trends shown in the graph above. Describe each trend briefly
but with sufficient detail to show your understanding of the processes involved.
i. (2 points)
ii. (2 points)
2. Define the following terms (2 points each):
a. Water Stress
b. Dobson Unit
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3. According to the IPCC A2 scenario, in 2100, the atmospheric CO2 level will be
approximately 800ppm. Based on this information, answer the questions that follow:
a. Calculate the pH of pristine rainwater using the A2 value for 2100. Show your
work in detail and state all your assumptions (5 points).
b. For an 800ppm CO2 atmosphere, how will each of these factors be affected
(please answer simply as “increase” or “decrease” or “no change”):
i. Ocean pH (1 point)
ii. Carbonate (CO32-)concentration (1 point)
iii. Carbonic acid (H2CO3*) concentration (1 point)
iv. Calcite saturation concentration (1 point)
v. Aragonite formation (1 point)
c. What is IPCC (1 point)?
d. Briefly explain the fate of corals in this scenario based on the chemistry involved
(3 points)?
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4. Study profile A and B and answer the questions that follow (2 point each):
A
B
a. Which profile best describes the vertical structure of the ocean with respect to
temperature? Why?
b. Which profile best describes the vertical structure of the ocean with respect to
salinity? Why?
c. Which profile best describes the vertical structure of the ocean with respect to
density? Why?
d. Which profile best describes the vertical structure of the ocean with respect to
dissolved inorganic N or P? Why?
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5. True or False (1 point each):
a. ______ The density of water increases with decreasing temperature.
b. ______ Salinity and temperature are the key determinants of seawater density.
c. ______ Major ocean deep currents are controlled primarily by wind.
d. ______ Ionic ratios of salts are exactly the same for different parts of the ocean.
e. ______ Freezing at the poles does not affect seawater salinity.
f. ______ Terrestrial ecosystems will bear most of the burden of expanding human
population.
g. ______ Increased precipitation over the ocean with decrease seawater density.
h. ______ Iron fertilization is expected to lessen ocean acidification.
i. ______ The agriculture sector is by far the biggest user of freshwater.
6. Explain the stability/instability of the troposphere and stratosphere (3 points).
7. Study the figure below and answer the questions that follow:
a. What might explain the inflection in the curve shown in (a) (2 points)?
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8. Biodiversity:
a. What are the three levels of Biodiversity (3 points)?
b. Name two factors most directly implicated in changes in Biodiversity (2 points).
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