Question 1
Gene interactions in which an allele of one gene modifies or prevents expression of alleles of another gene is known as ________.
◦ pleiotropy
◦ incomplete dominance
◦ codominance
◦ epistasis
◦ incomplete penetrance
Question 2
In certain goat breeds, appearance of a chin beard is a sex-influenced trait. Recall that bearding is inherited as an autosomal trait determined by two alleles,
B1 and
B2, and females must be homozygous for the bearded allele,
B2, to have a beard. What genotypes must a bearded billy goat (male) and a beardless female goat have if they have a bearded female offspring?
◦ The bearded billy goat must be heterozygous for the bearded allele, while the beardless female must be homozygous for the bearded allele.
◦ Both the bearded billy goat and beardless female must be heterozygous for the bearded allele.
◦ The bearded billy goat could be heterozygous or homozygous for the bearded allele, while the beardless female must be heterozygous for the bearded allele.
◦ Both the bearded billy goat and beardless female must be homozygous for the bearded allele.
◦ The bearded billy goat could be heterozygous or homozygous for the bearded allele, while the beardless female must be homozygous for the bearded allele.
Japanese Chin
Diverticulosis. Figure illustrates external and internal appearance of diverticula.
Pap smear. Cells of the cervix (shown in the center) change in appearance as they progress through
A pedigree for an autosomal dominant trait
A pedigree for an X-linked dominant trait. Affected males produce all affected daughters and no affe
Homozygous or heterozygous for the dominant trait?