Basics Week One Flashcards
DIPLOID
two copies of each gene
(maternal & paternal)
Haploid
one copy of each gene (gamete)
GENE
a fragment of DNA encoding RNA
ALLELES
alternative forms of same gene (b-globin & sickle-cell b-globin)
wild-type & mutant allele
HOMOLOGUES
copies related by descent;
HOMOLOGOUS
same gene in different
species (eg. chimpanzee
and human b-globin genes)
ORTHOLOGOUS
Genes found in different species that share a common ancestor and often have similar functions
Paralogus
Twin genes within the same species that are similar to each other but they have different jobs or functions
Analogus
Gene performs similar function in different species but no common ancestor
Can happen by chance or convergent evolution
Haplotype
DNA variations (polymorphisms),
that tend to be inherited together.
Incomplete dominance
when the heterozygous has a phenotype that is in between the phenotypes of the two homozygous.
codominance
when both alleles of the heterozygous contribute equally to the phenotype.
Epistasis
One gene mask the expression of another gene
Penetrance
Identical genes produce different expression patterns
Incomplete penetrance
When the presence of a particular allele results in a defined phenotype in some but not all individuals.
