extensions and modifications of mendel gene exam 5 lemon

epistasis

an allele of one gene masks the phenotype caused by alleles of a different gene

overriding gene is _ to the masked gene

epistatic

the masked gene is _ to the overriding gene

hypostatic

recessive epistasis

9:3:4 ratio
homozygous recessive for one gene causes homo recessive for both genes

complete dominance

hetero phenotype is the same as the phenotype for one of homozygotes

incomplete dominance

hetero phenotype is intermediate between two homozygous phenotypes

neither allele is dominant or recessive

Codominance

Heterozygous phenotype includes both of the homozygous phenotypes

Neither allele is dominant or recessive to the other

penetrance

percentage of a population with a particular genotype that shows the expected phenotype

expressivity

degree or intensity with which a particular genotype is expressed in a phenotype

null mutation

function of gene product is completely abolished

Hypomorphic mutation

function of gene product is partially abolished

Hypermorphic mutation

function of gene product is increased or expression of gene occurs in ectopic sites in the body