Scientists describe the processes of photosynthesis and cellular respiration as "being interrelated". What is this statement most likely referring to? A. The reactants of both processes are the same.

B. The products of both processes are the same.

C. The products of each process are the reactants to the other.

D. The processes occur at the same time.

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.