13. Mendelian Genetics

Calculate the probability of 2 heterozygous (Rr) parents having 3 homozygous recessive (rr) offspring.

What is the probability that a plant from a monohybrid cross of heterozygous parents, is homozygous dominant OR homozygous recessive?

A blue-eyed female that is homozygous recessive and a brown-eyed male that is heterozygous mate, producing two offspring. What is the probability that one child will have blue eyes AND one will have brown eyes? (Eye color is controlled by a single gene).

A homozygous dominant male has a child with a heterozygous female. What is the probability that the child will have the same genotype as its father OR its mother?

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.

Flower position, stem length, and seed shape are three characters that Mendel studied. Each is controlled by an independently assorting gene and has dominant and recessive expression as indicated in Table 14.1. If a plant that is heterozygous for all three characters is allowed to self-fertilize, what proportion of the offspring would you expect to be each of the following? (Note: Use the rules of probability instead of a huge Punnett square.) a. homozygous for the three dominant traits b. homozygous for the three recessive traits c. heterozygous for all three characters d. homozygous for axial and tall, heterozygous for seed shape