Exam 13: Observing Patterns in Inherited Traits

-The accompanying illustration shows the F2 phenotypes from a monohybrid cross in snapdragons. What type of inheritance produces such an outcome?

True-breeding yellow guinea pigs crossed with true-breeding white ones produce only cream-colored offspring. This pattern indicates incomplete dominance. Rough hair is found to be dominant to smooth hair. Give the F1 and F2 genotypic and phenotypic ratios of a cross of a smooth, white guinea pig with a homozygous, rough, yellow guinea pig.

Genes at one locus that affect the expression of genes at a different locus are said to be

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with purple flowers crossed with a tall plant with purple flowers produces 3/4 tall purple and 1/4 tall white. What is the genotype of the parents?

Consider the work Mendel did with his pea plants. Why is the study of human genetics much more difficult?