gene interaction quiz

incomplete dominance

heterozygote has an intermediate phenotype

gain of function

make mutant gene product that interferes with function of the normal gene product

allelic series / multiple alleles

the set of forms of one gene differing in their DNA sequence or expression or both

full/complete dominance

an allele that expresses itself the same in single copy (heterozygote) as in double copy (homozygote)

null mutation

a mutation that results in complete absence of function for the gene

dominant negative

a mutant allele that in a single dose (heterozygote) wipes out gene function by a spoiler effect on the protein

incomplete dominance

a form of gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype

codominance

a situation in which a heterozygote shows the phenotypic effects of both alleles equally

temperature sensitive

a conditional mutation that produces the mutant phenotype in one temperature range and the wild type phenotype in another temperature range

permissive temperature

the temperature at which a temperature sensitive mutant allele is expressed that same as the wild-type allele

restrictive temperature

the temperature at which a temperature sensitive mutation expresses the mutant phenotype

penetrance

the proportion of individuals with a specific genotype that manifest the genotype at the phenotype level

expressivity

the degree to which a particular genotype is expressed in the phenotype, the phenotype varies in intensity or other measure

pleiotropic

mutations that affect multiple phenotypes are

haploinsufficient

genes that require two functional alleles

dominant negative

mutations produce a gene product that interferes with the function of the WT gene product

codominance

both phenotypes are present in a heterozygote

incomplete penetrance

not all individuals of a mutant genotype express the mutant phenotyoe

dihybrid cross ratio

9 3 3 1

recessive epistasis

one mutation over rules the effect of another mutation

recessive epistasis

genes in the same pathway

complementation test

a test if two mutant strains that cant make blue pigment have mutations in the same or different genes

complementation

production of wild type phenotype when two full or partial haploid genomes are united in the same cell

no gene interaction

9 3 3 1

genes in the same pathway

9 7

9 3 4

recessive epistasis

epistasis

where the expression of one gene is modified by the expression of one or more other genes (independently inherited genes)

12 3 1

dominant epistasis

suppressor

a secondary mutation that can cancel the effect of a primary mutation resulting in wildtype phenotype

revertants

a mutant gene that regains a formed capability by undergoing further mutation

modifier

a mutation at a second locus that changes the degree of expression of a mutated gene at a first locus

synthetic lethals

refers to a double mutant that is lethal, whereas the component single mutations are not

complete dominance

a pea plant that is either homozygous dominant or heterozygous for a trait always displays the dominant phenotype

incomplete dominance

in humans one sickle cell (mutant) allele causes moderate severity disease, and two sickle cell alleles have severe anemia

dominant negative

brittle bone disease is a condition where the monomer protein that makes up collagen results in all mutant collagen proteins if one allele is mutant

recessive lethal

zebrafish can carry an allele for a a recessive mutation called zombie. in a cross between 2 heterozygotes the offspring are 1/3 homo for wildtype 2/3 hetero and there are not viable double mutants

codominance

parents with blood types AA and BB are phenotypically A and B respectively. they have a child that is blood type AB with the phenotype AB

haploinsufficient

in a mouse model, there is a gene that encodes for transcription factor that normally turns on of an essential gene. when the mouse is heterozygous for the gene, the transcription factor does not make enough of the protein, resulting in a mutant phenotype