Question

shrimp are primary consumers that feed on photosynthetic organisms. why would these organisms likely be found only in shallow ocean zones? (3 points)
the fast currents in deeper ocean zones would kill photosynthetic organisms.
the amount of oxygen in deeper ocean zones is too high for shrimp to breathe.
the amount of light in deeper ocean zones is too dim to support photosynthesis.
the high water pressure in deeper ocean zones would likely prevent photosynthesis.

1. (01.03 hc)

a scientist discovers a new species of marine bacteria that do not require oxygen to survive. in fact, dissolved oxygen in the water is actually toxic to these bacteria. predict what region of the ocean this species would most likely inhabit, and select the best explanation. (3 points)
deep because there is less oxygen exchange
deep because there are more oxygen-containing compounds
shallow because more oxygen is produced
shallow because low pressure increases dissolved gas

Explanation:

First Question (Shrimp and Photosynthetic Organisms)

Photosynthetic organisms need light for photosynthesis. Deeper ocean zones have very little light, so these organisms (and shrimp that feed on them) are in shallow zones where light is sufficient. The option "The amount of light in deeper ocean zones is too dim to support photosynthesis" matches this logic. Other options: fast currents killing them, oxygen levels for shrimp, or pressure preventing photosynthesis are less relevant to photosynthetic organisms' light requirement.

The bacteria don't need oxygen and oxygen is toxic to them. Deeper ocean zones have less oxygen exchange (so less dissolved oxygen, which is toxic to them). Shallow zones have more oxygen (from exchange or production), which is toxic. So the bacteria would be in deep zones with less oxygen exchange. The option "Deep because there is less oxygen exchange" fits. Other options: deep with more oxygen compounds (wrong, they don't need oxygen), shallow with more oxygen produced (toxic), shallow with low pressure (pressure not the issue here) are incorrect.

Answer:

The amount of light in deeper ocean zones is too dim to support photosynthesis.

Second Question (Marine Bacteria)