BIO 1201 GREGG EXAM 3 2026 CELL BIOLOGY
AND GENETICS PRACTICE SET ANSWERS FULL
SOLUTION
◉ when expression of a gene at one locus alters the phenotypic
expression of a gene at a second locus
Answer: epistasis
◉ when multiple genes independently affect a single trait
Answer: polygenic inheritance
◉ example of epistasis
Answer: labrador retriever coat color: one gene determines the
pigment color and the other gene determines if the pigment is
deposited in the hair
◉ example of polygenic inheritance
Answer: over 180 genes affect height
◉ heterozygous individuals who carry the recessive allele but are
phenotypically normal
Answer: carriers
, ◉ recessive disorders show up only in individuals ____
Answer: homozygous for the allele
◉ example of recessive disorder
Answer: albinism
◉ example of dominant disorder
Answer: achondroplasia (dwarfism)
◉ degenerative disease of the nervous system
Answer: Huntington's disease (has no effect until the individual is 40
years of age)
◉ someone with two x chromosomes is a ___
Answer: female
◉ someone with one x and one y chromosome is a ___
Answer: male
◉ a gene that is located on either sex chromosome is called a
Answer: sex-linked gene
AND GENETICS PRACTICE SET ANSWERS FULL
SOLUTION
◉ when expression of a gene at one locus alters the phenotypic
expression of a gene at a second locus
Answer: epistasis
◉ when multiple genes independently affect a single trait
Answer: polygenic inheritance
◉ example of epistasis
Answer: labrador retriever coat color: one gene determines the
pigment color and the other gene determines if the pigment is
deposited in the hair
◉ example of polygenic inheritance
Answer: over 180 genes affect height
◉ heterozygous individuals who carry the recessive allele but are
phenotypically normal
Answer: carriers
, ◉ recessive disorders show up only in individuals ____
Answer: homozygous for the allele
◉ example of recessive disorder
Answer: albinism
◉ example of dominant disorder
Answer: achondroplasia (dwarfism)
◉ degenerative disease of the nervous system
Answer: Huntington's disease (has no effect until the individual is 40
years of age)
◉ someone with two x chromosomes is a ___
Answer: female
◉ someone with one x and one y chromosome is a ___
Answer: male
◉ a gene that is located on either sex chromosome is called a
Answer: sex-linked gene
