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.
A family pedigree of a dominant trait
Female choice based on male appearance.
Eye Color Is a Sex-Linked Trait in Drosophila (Part 3)
Marasmus The emaciated appearance of this child is a sign (and symptom) of marasmus
A graphic depiction of predisposing alleles characteristic of a threshold trait within a population,
goat digestive