Page 88 Dihybrid Problems 2 In rabbits black

Page 88, Dihybrid Problems #2 In rabbits, black coat color is due to a dominant gene B, brown coat color is due to a recessive gene b. Short hair is due to a dominant gene S, long hair to its recessive allele s. In a cross between 2 heterozygous black, short haired rabbits, what would be the phenotypic ratio of the offspring? 1

B – black coat S – short hair b – brown coat s – long hair Cross between 2 heterozygous black, short haired rabbits B b. Ss Ss Bb. Ss x Bb. Ss BS Bs b. S bs 2

#1 Results BS Bs b. S bs BS BBSs Bb. SS Bb. Ss Bs BBSs BBss Bb. Ss Bbss b. S Bb. Ss bb. SS bb. Ss bs Bb. Ss Bbss bb. Ss bbss 3

B – black; b – brown; S – short; s - long BS BS Bs b. S bs BBSS BBSs Bb. SS Bb. Ss Black (B), short (S) Black (B), long (s) Bs b. S bs BBSs Bb. SS BBss Bb. Ss Bbss bb. SS bb. Ss bbss Brown (b), short (S) Brown (b), long (s) 9: 3: 3: 1 4

Page 88, Dihybrid Problems #2 In horses, black color is dependent upon a dominant gene B, and chestnut upon its recessive allele b. The trotting gait is due to a dominant gene T and the pacing gait to its recessive allele t. if a homozygous black pacer is mated to a homozygous chestnut trotter, what will the genotype and phenotype of the F 1 generation be? 5

B – black T - trotting Homozygous x black pacer BBtt x Bt Bt b – chestnut t – pacing Homozygous chestnut trotter bb. TT b. T 6

B – black; b – chestnut; T – trotting; t - pacing Bt Bt b. T Bb. Tt Bb. Tt b. T Bb. Tt All offspring Bb. Tt — Black Trotters Bb. Tt 7

Page 88, Dihybrid Problems #3 If two F 1 individuals from #3 were mated, what would be the phenotypic ratio of the offspring? Bb. Tt BT Bt b. T bt x Bb. Tt BT Bt b. T bt 8

B – black; b – chestnut; T – trotting; t - pacing BT Bt b. T bt BT BBTt Bb. TT Bb. Tt Bt BBTt BBtt Bb. Tt Bbtt Bb. TT Bb. Tt bb. TT bb. Tt bbtt b. T bt Bb. Tt Bbtt 9: 3: 3: 1 9

Page 88, Dihybrid Problems #4 An organisms has the genotype AABb. It is crossed with an individual with the genotype Aabb. What type of gametes can be produced by these two individuals? AABb AB Ab x Aabb Ab Ab ab ab 10