Typical ratios resulting from epistatic interactions in dihybrid crosses would be . Typical ratios resulting from epistatic interactions in dihybrid crosses would be . 3:1, 1:1 9:3:3:1, 1:2:1 9:3:4, 9:7 1:2:2:4:1:2:1:2:1, 1:2:1 1:1:1:1, 1:4:6:4:1

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.