Topic 8-2 Flashcards
different forms of a gene that exist in a locus
allele
the most common allele in the population is considered to be the:
wildtype allele
if identical alleles are present on both homologous chr, the organism/cell is said to be ________ for that allele
homozygous
if one allele is wildtype and the other allele is not, the organism/cell is said to be ________ for that allele
heterozygous
the known mutant alleles for a given gene plus its wild type allele are referred to as:
an ‘allelic series’ or ‘multiple alleles’
a situation where a cell/organism has only one copy of a gene. ex: a deletion or the gene occurs naturally in one copy of a homologous chr but not the other (X and Y)
hemizygous
dominant and recessive describe the relationships between:
two alleles of the same gene
what if an individual has two mutant alleles that are different from each other?
this is referred to as ‘heteroallelic’
alleles of genes do not always exhibit simple dminance/recessive relationships. sometimes there is an intermediate/blended phenotype in the heterozygote. this is known as:
incomplete dominance or semi-dominance
a situation where heterozygotes simulteneously express the penotypes of both alleles (ex: blood type)
codominant
AB blood is codominant
who designated five mutants classes as “morphs”?
HJ Muller
what are amorphs?
refers to the complete loss of a gene (null mutation). ex: deletion of a gene, missense point mutation, nonsense point mutations.
what are hypomorphs?
a mutation where the allele is still partially functional, but not at the level of the wild type gene (partial loss of function or leaky)
what are hypermorphs?
a mutation where the gene is active at a level higher than the wildtype gene (gain of function)
a repressor of muscle growth
myostatin
