13. Mendelian Genetics

Which of the following statements is correct in describing the terms monohybrid cross and dihybrid cross?

Which of the following phenomena is a consequence of independent assortment?

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny created by crossing BbTt × BBtt will be expected to have black fur and long tails?

DRAW IT Two pea plants heterozygous for the characters of pod color and pod shape are crossed. Draw a Punnett square to determine the phenotypic ratios of the offspring.

A plant with orange, spotted flowers was grown in the greenhouse from a seed collected in the wild. The plant was self-pollinated and gave rise to the following progeny: 88 orange with spots, 34 yellow with spots, 32 orange with no spots, and 8 yellow with no spots. What can you conclude about the dominance relationships of the alleles responsible for the spotted and unspotted phenotypes? What can you conclude about the genotype of the original plant that had orange, spotted flowers?

In peas, purple flowers are dominant to white. If a purple-flowered, heterozygous plant were crossed with a white-flowered plant, what is the expected ratio of genotypes and phenotypes among the F1 offspring? If two of the purple-flowered F1 offspring were randomly selected and crossed, what is the expected ratio of genotypes and phenotypes among the F2 offspring?