Inheritance Patterns Flashcards
single gene
what are genetic complexities beyound dominant and recessive?
Alleles have a dominance hierarchy that has to be determined if more than one allele is present (if 2 or more alleles are on the local)
What is MC1R ?
melanoreceptor gene - Ed is donimamnt black or ee which is a true red (only omozygous res will show red
where is the pigment diposited
the the root of hair or skin
what are the two different types of MC1R pigments
Phaeomelanin - producing red, yellow and cream
Eumelanin - producing black, brown and grey
when does black occur
in every heterozygous dominant pattern and recessive pattern
red only shows up in homozygous recessive
what is MC1R E+
wild type - the colour is influenced by other genes
What is the dominance hierarchy of alleles
ED>E+>e
what colours do they make
EDED- black
E+E+ - brown/wild type
ee - red
EDE+ black
EDe - black
E+e - brownish
what is codominant?
both phenotypes expressed together but observed seperately
what is incomplete dominance
both phenotypes are expressed as a blended appearnce
what are some autosomal recessive generalizations
- most are enzyme deficiencies (inborn errors of metabolism)
- phenotype is generally consistent
symptoms are severe (present at birth and often lethal)
consanguinity common (from ancestors)
what does autosomal recessive mean
recessive because neither parent actually looks infected
what are the exceptions for consistent phenotypes
von willebrand disease
cone-rod dystrophy
what are examples of carrier detection tests?
breedin tests(NEED TO KNOW DISEASE), direct tests(biochemical, DNA tets for the mutation) and indirect linkage tests for DNA
what is the breeding test
mate a sire of interest to either affected dams or heterozygous carrier dams and see if any affected offspring is born
if yes the sire is a carrier
