Question

1.
which of the following is not a factor in determining where an
organism lives in an aquatic ecosystem
○ oxygen
a
○ b
distance
○ c
sunlight
○ d
temperature
2.
how does the current of the headlands of a river compare
with the parts of a river farther downstream near the mouth?
○ the headlands have a slower current and less oxygen
a
○ b
the headlands have a faster current and more oxygen ○ c
the headlands have a slower current and more oxygen ○ d
the headlands have a faster current and less oxygen
3.
in which of the following aquatic ecosystems are both littoral
and benthic zones most likely found?
○ open ocean
a
○ b
coral reef
○ c
lake
○ d
none of the above

Explanation:

Question 1

In an aquatic ecosystem, oxygen (affects respiration), sunlight (affects photosynthesis and light availability), and temperature (affects metabolism and survival) are key factors determining an organism's habitat. Distance is not a direct factor related to an organism's living conditions in the aquatic environment.

River headlands (source/upper parts) have steeper gradients, so faster currents. Faster currents increase water agitation, allowing more oxygen to dissolve. Downstream near the mouth, currents slow. So headlands have faster current and more oxygen.

Littoral zone is the shallow near - shore area, and benthic zone is the bottom zone. Lakes have a littoral zone (near the shore, shallow) and a benthic zone (the lake bottom). Open ocean has pelagic zones mainly, and coral reefs have different zonation but lakes are more likely to have both littoral and benthic zones clearly defined as such.

Answer:

B. distance

Question 2