Multiple Choice
Why do some water masses in subsurface oceans have little or no oxygen?
A) Rates of photosynthesis are low in overlying waters, limiting the availability of oxygen.
B) Rates of photosynthesis are high in overlying waters, supporting high rates of respiration in waters that deplete the oxygen there.
C) Waters underneath the surface oceans are cold and so have a limited capacity to carry oxygen in solution.
D) Large carnivores deplete oxygen in subsurface oceans via their high rates of oxygen metabolism.
Correct Answer:

Verified
Correct Answer:
Verified
Q19: The high specific heat of water means
Q20: Recent studies indicate that the addition of
Q21: Chemistry in lake biomes will vary primarily
Q22: Most terrestrial biomes are defined by their
Q23: If rates of nitrogen fixation increased tenfold
Q25: Because tropical plants have very high species
Q26: The growing season is that portion of
Q27: Similar to the tundra, but without a
Q28: Autotrophs remove _ from the air and
Q29: Tropical biomes have evolved over _ years.