2 Traits With Dominance (pp ) Identify alleles (letters) Identify alleles (letters) Write out cross Write out cross Set up Punnett Square Set up Punnett Square 4 possible gametes for each parent 4 possible gametes for each parent 16 square Punnett Square 16 square Punnett Square Fill in Punnett Square Fill in Punnett Square Give Results Give Results

Set C- 2 Traits With Dominance T=Tall, t=Short T=Tall, t=Short R=Round, r=Wrinkled R=Round, r=Wrinkled TtRr x TtRr TtRr x TtRr Possible gametes Possible gametes Male- Male- TR, Tr, tR, tr TR, Tr, tR, tr Female- Female- TR, Tr, tR, tr TR, Tr, tR, tr TRTrtRtr TR Tr tR tr

Set C- 2 Traits With Dominance TtRr x TtRr TtRr x TtRr Pheno- Pheno- 9 Tall Round 9 Tall Round 3 Tall Wrinkled 3 Tall Wrinkled 3 Short Round 3 Short Round 1 Short Wrinkled 1 Short Wrinkled This is a dihybrid cross (hybrid for 2 traits) This is a dihybrid cross (hybrid for 2 traits) Phenotype will always be 9:3:3:1 Phenotype will always be 9:3:3:1 TRTrtRtr TRTTRRTTRrTtRRTtRr TrTTRrTTrrTtRrTtrr tRTtRRTtRrttRRttRr trTtRrTtrrttRrttrr

Set D- Incomplete Dominance p 184 Neither allele dominates other Neither allele dominates other White x White = White White x White = White Red x Red = Red Red x Red = Red White x Red = Pink White x Red = Pink Offspring is a mix of 2 traits Offspring is a mix of 2 traits Phenotype will be the same as the Genotype Phenotype will be the same as the Genotype RR = red RR = red rr = white rr = white Rr = pink Rr = pink

Codominance p 184 Both alleles are expressed Both alleles are expressed BB = black BB = black WW = white WW = white BW = black & white BW = black & white Black feathers x white feathers = black and white feathers Black feathers x white feathers = black and white feathers

Set E- Sex Determination Sex Chromosomes Sex Chromosomes Determines sex Determines sex X & Y chromosomes X & Y chromosomes Males = XY Males = XY Females = XX Females = XX Humans = 2 (1 pair) Humans = 2 (1 pair) Autosomes Autosomes All other chromosomes All other chromosomes Humans = 44 (22 pair) Humans = 44 (22 pair) Karyotype- shows chromosomes (see page 236) Karyotype- shows chromosomes (see page 236)

Set F- Sex Linked Traits Determined by recessive alleles located on the “X” chromosome Determined by recessive alleles located on the “X” chromosome Occur more often in males (need only 1 recessive allele) Occur more often in males (need only 1 recessive allele) Ex. male = X n Y Ex. male = X n Y Ex. female = X n X n Ex. female = X n X n

Set F- Sex Linked Traits Possible genotypes Possible genotypes Normal Male = X N Y Normal Male = X N Y Male with trait = X n Y Male with trait = X n Y Normal Female = X N X N Normal Female = X N X N Carrier Female = X N X n Carrier Female = X N X n Female with trait = X n X n Female with trait = X n X n

Set G- Multiple Alleles More than 2 alleles for a trait (in the populations gene pool) More than 2 alleles for a trait (in the populations gene pool) Each individual will still have only 2 alleles for the trait Each individual will still have only 2 alleles for the trait C = full color C = full color h = himalayan h = himalayan a = albino a = albino Example- some rabbits Example- some rabbits CC, Ch, or Ca = full color CC, Ch, or Ca = full color hh, ha = himalayan hh, ha = himalayan aa = albino aa = albino

Set H- Human Blood Type Multiple alleles Multiple alleles A, B, O A, B, O Dominance Dominance A & B dominant to O A & B dominant to O Codominance Codominance A & B codominant to each other A & B codominant to each other

Set H- Human Blood Type TypeGenotype TypeGenotype A AA, AO AA, AO B BB, BO BB, BO AB AB O OO OO

Genetic Disorders Huntington disease- Huntington disease- Caused by a single dominant allele (H) Caused by a single dominant allele (H) Sickle cell anemia- Sickle cell anemia- Autosomal recessive Autosomal recessive Colorblindness (red– green)- Colorblindness (red– green)- Sex linked trait, recessive allele on X chromosome Sex linked trait, recessive allele on X chromosome

Genetic Disorders Hemophilia- Hemophilia- Sex linked trait, recessive allele on X chromosome Sex linked trait, recessive allele on X chromosome Down syndrome- Down syndrome- Nondisjunction of 21 st pair of chromosomes Nondisjunction of 21 st pair of chromosomes No disjunction- failure of chromosomes to separate during meiosis No disjunction- failure of chromosomes to separate during meiosis