Mendel used dihybrid crosses to test the idea that alleles for two different characters assort independently.  In a typical dihybrid cross (such as RrTt x RrTt), what proportions of phenotypes would be expected in the offspring? Select one: a. 9:3:3:1 b. 4:4:4:4 c. 2:2 d. 3:1 e. 100% dominant phenotype

Examine a two-gene cross that follows simple Mendelian inheritance of freckles and eyebrow shape between a woman with genotype Mmpp and a man with genotype mmpp. How many phenotypes are possible in their offspring and in what ratio?

In four-o'clocks, the allele for red flowers is incompletely dominant over the allele for white flowers, so all heterozygotes have pink flowers. If you cross a white flower with a pink flower, what is the phenotypic ratio of the F1 generation (i.e., the offspring that are produced)?   a. 1 red: 2 pink: 1 white   b. 0 red: 2 pink: 2 white   c. 1 red: 0 pink: 3 white   d. 1 red: 1 pink: 2 white   e. 0 red: 4 pink: 0 white

In mice, black fur (B) is dominant over brown fur (b). Two black mice had only black offspring. Which of the following offspring genotypes could result from the parental cross? Select all that apply. A. BB B. Bb C. bb