Oxygen levels in the photic zone fluctuate over the course of a 24-hour period. If you were measuring dissolved oxygen over the course of the day, when would you expect to see the lowest levels of oxygen and why?
A. Early evening when animals come to feed and disturb the surface waters.
B. Early afternoon when the surface water warms up and sinks to the bottom.
C. Mid-morning because fish are most active and their respiration rates are highest.
D. Mid-afternoon because the activity of the Calvin cycle (the dark reactions) of photosynthesis are at their peak.
E. During the night because the light reactions of photosynthesis are inactive.
Answer: E
You might also like to view...
Why might a soil that has a sufficient concentration of a mineral element, for example, calcium, not have sufficient
availability of the element to maximize plant growth rates?
What will be an ideal response?The ____ is a protective structure where sperm cells are formed in bryophytes and some other plants
a. antheridium b. stoma c. strobilus d. sporangium e. archegonium
Mosses have threadlike structures, called ____, that hold the gametophyte in place
a. mycorrhizae b. fronds c. rhizoids d. sporangia e. rhizomes
A solution of pH 3 is 100 times more acidic than a solution of pH 5.
Answer the following statement true (T) or false (F)