If a diploid cell has 12 chromosomes in prophase I, how many chromatids will the cell have at the completion of anaphase I and anaphase II? #1
always 12

#2
12 and 6

#3
36 and 24

#4
24 and 12

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.