Exam 2 Questions
and Complete
Answers Graded
A+
Denning [Date] [Course title]
, Loss of function Mutations - Correct Ans: Cause a gene to lose some or all of it's normal function
Hypomorphic mutations - Correct Ans: Genes that have lost only some of their function
Null mutations - Correct Ans: Genes that have lost all of their function
Haplo-sufficient - Correct Ans: One (haplo) copy is sufficient to produce the wild-type phenotype in the
heterozygous genotype
Fully dominant mutations - Correct Ans: Phenotype of a fully dominant mutation is seen in both
heterozygous and homozygous dominant individuals.
Gain-of-function - Correct Ans: gene product acquires a new function or express increased wild type
activity
Loss-of-function - Correct Ans: there is a significant decrease or complete loss of functional gene
product
Incomplete dominance - Correct Ans: phenotype of the heterozygote is intermediate between the
phenotypes of the two homozygotes on some quantitative scale (color, size, etc)
Codominance - Correct Ans: Phenotypes of both alleles are fully expressed in the heterozygote and
leads to a different phenotype than either homozygotes.
Allelic series of the C gene - Correct Ans: Wild type allele: C, produces full coat color
c^ch: produces a dilute phenotype, chinchilla
c^h: produces phenotype called Himalayan with little pigment on the body but full color on the
extremities (non functional at higher body temps).
c:Fully recessive, null allele and produces an albino phenotype
complementation tests - Correct Ans: Determine if mutations that cause the same phenotype are in the
same or different genes.