Chapter 4 Flashcards
Wild-Type
allele that occurs more frequently in population
Mutations
mutant allele contains modified genetic information and often specifies an altered gene product
Loss-of-function Mutations
mutation in gene causes change in conformation enzyme
if complete, results in null allele
Gain-of-function Mutations
some mutations enhance function of wild-type allelic function
Neutral Mutation
the gene product presents no change to phenotype
Intermediate phenotype
results from cross between parents with contrasting traits
Incomplete/partial dominance
neither allele is dominant
Codominance
two alleles of a single gene produce two gene products
Multiple Alleles
three or more alleles of the same gene
Lethal Alleles
genes required for organism’s survival, if recessive, heterozygotes live
Epistasis
expression of one gene or gene pair masks/modifies effect of another gene pair
Dominant Epistasis
dominant allele at one loci masks an allele at second loci
Complementation Analysis
determines if two mutations are in the same gene
Pleiotropy
expression of a single gene has multiple phenotypic effects (ex Marfan)
X-Linkage
genes present on X chromosome
Lethal X-linked recessive Disorders
observed only in males, females are heterozygotes (ex Duchenne)
Sex-Limited Inheritance
patterns of gene expression affected by gender
Penetrance
percentage of expression of mutant genotype in population
Expressivity
range of expression of mutant phenotype
Translocation/Inversion
location of gene may modify its expression
Genetic Anticipation
genetic disease has earlier onset and increased severity with each succeeding generation
Extranuclear Inheritance
inheritance patterns which vary from traditional biparental inheritance of nuclear genes
Organelle Heredity
organisms phenotype determined by genetic information expressed in maternal gamete
Maternal Effect
organisms phenotype determined by genetic information expressed in maternal gamete
Heteroplasmy
cell may or may not have mutant genes in organelles
