long version
long version
PATTERNS OF INHERITANCE
dominant/recessive (classical Mendelian)
TEST CROSS
monohybrid (A_ X aa)
dihybrid (A_B_ X aabb)
genetic mapping
INCOMPLETE DOMINANCE/CODOMINANCE
three genotypes in both (additional genotype associated with heterozygote)
incomplete: heterozygote phenotype is blend of two homozygous traits
use capital letters and 'prime'
eg. R = red R' = white RR' = pink
codominance: heterozygote shows both traits at the same time
use different letters
eg. B = black W = white BW = checkered black & white
practice
SEX-LINKED INHERITANCE
-many more characters on X than Y
-males are hemizygous for sex chromosomes
-sex-linked disorders often recessive
-in pedigrees, parents unaffected, sons but rarely daughters affected
colour-blindness
Duchenne muscular dystrophy
royal hemophilia pedigree
problems
Magic Six in class