The processes of photosynthesis and respiration are considered a cycle because: a
Photosynthesis produces ATP while respiration consumes ATP
b
Photosynthesis happens during the day and respiration only occurs at night
c
The products of photosynthesis are used as the reactants of cellular respiration
d
Photosynthesis produces CO2 while respiration requires CO2

c.The products of photosynthesis are used as the reactants of cellular respiration

Explanation:

hope this helps

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

this is math not biology xd