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 recessive trait.
Ancestral versus shared derived characters involving a molecular trait.
Coral reefs are influenced by sea surface temperatures.
Hints of Earth’s Early Appearance
Darwin was deeply influenced by his stop in the Galapagos Islands.
DO NOT BRING DOWN YOUR MASK TO THE CHIN