Question

the nature of science, the chemistry of life and ecology
which biogeochemical cycle is used in the creation of nucleic acids?
a) water cycle
b) phosphorus cycle
c) primary productivity
d) nitrogen cycle
question 20 (5 points)
listen
which of the following correctly orders the zone of depths in a lake from shallowest to deepest?
a) littoral, profundal, limnetic
b) limnetic, littoral, profundal
c) profundal, littoral, limnetic

Explanation:

First Question (Biogeochemical Cycle for Nucleic Acids)

Nucleic acids (DNA, RNA) contain phosphorus (in phosphate groups). The phosphorus cycle involves the movement of phosphorus, which is used in nucleic acid synthesis. The water cycle (A) is about water movement, primary productivity (C) is about energy conversion in ecosystems, and the nitrogen cycle (D) involves nitrogen (key for proteins/amino acids, not nucleic acids' main component besides sugar and base, but phosphorus is critical for the phosphate - sugar backbone of nucleic acids).

Second Question (Lake Zones Order)

(Note: Assuming the fourth option (not fully visible but standard lake zones order is Littoral, Limnetic, Profundal) - but from given options, likely a typo or mis - option. However, if we consider standard lake zones: Littoral (shallow, near shore), Limnetic (open water, sunlit), Profundal (deep, no light). But from the given options, there's a mistake. If we assume a misprint and the correct order from shallowest to deepest is Littoral, Limnetic, Profundal. But among the given options (A: Littoral, profundal, limnetic; B: Limnetic, littoral, profundal; C: Profundal, littoral, limnetic) - none is correct. But if we have to choose from given, maybe a mis - option. However, the standard order is Littoral (shallowest, near shore, where light reaches bottom), then Limnetic (open water, sunlit, deeper than littoral but still sunlit), then Profundal (deepest, no light). So if there was an option Littoral, Limnetic, Profundal, that would be correct. But from the given, perhaps a typo in the options. If we assume that option A has a misprint (profundal and limnetic reversed), but as per given, there's an error. But if we proceed with standard knowledge, the correct order from shallowest to deepest is Littoral, Limnetic, Profundal.

Answer:

B) Phosphorus cycle