T10: non-mendelian genes

non-mendelian genes

• does not follow mendels traditional laws of inheritance

• display comlex inheritance patterns

incomplete dominance

when heterozygotes have intermediate phenotypes, in between the two homozygous phenotypes

• nothing is more dominant than the other

example of incomplete dominance

pink flower

codominance

when heterozygotes express both alleles phenotypes fully

• there are no intermediate phenotypes

pleiotropy

when one gene affects two or more seemingly unrelated phenotypic traits

permissive temperatures

temperatures that are cool

restrictive temperatures

temperatures that are too hot

are the darker areas hotter or cooler?

cooler becuase permissive temperaturs allow protiens to fold properly so dark pigments can be made. But temperatures that are oo hot doesnt allow proteins to fold properly so less/no pigment is made

expressivity

the degree to which the mutant character is expressed

• it varies between undividuals

incomplete penetrance

person has a dominant mutant allele but does not show the mutant phenotype at all

• looks like a wildtype

sex-influenced traits

interaction with sex hormones can cause different sexes to exhibit different frequencies, intensities, or timing of phenotypic expression

sex-limited

only one sex can show the mutant phenotype even tho it is an autosomal gene