Question

9. In snapdragons, red flower color is incompletely dominant to white and the heterozygote is pink. Normal broad leaves is incompletely dominant to narrow grass-like ones, and the heterozygous is intermediate width. IF a red-flowered, broad-leaved plant is crossed with a white-flowered, narrow-leafed one, list genotypic and phenotypic ratios of the following: a) Fi generation b) F2 generation 10. In humans, the allele for brown eyes (B) is dominant to the allele for blue eyes (b). a) A brown-eyed man marries a blue-eyed woman, and they have 6 children, all brown-eyed. b) What are the genotypes of all individuals in the family? c) A brown-eyed man, both of whose parents were brown-eyed, marries a brown-eyed woman. They had one blue-eyed child. What are the genotypes of all individuals? d) What are the chances that the first child of a marriage of two heterozygous brown-eyed parents will be blue-eyed? If the first child is brown-eyed, what are the chances that the second child will be blue eyed?

Could you please explain using Punnett squares? Thanks!!

Answer 1

Parents-

RRBB x rrbb

Red flower with broad leaves x White flower with narrow leaves

F1- RrBb

all Pink flowers with intermediate length

selfing- RrBb x RrBb

gametes- RB, Rb, rB, rb

	RB	Rb	rB	rb
RB	RRBB	RRBb	RrBB	RrBb
Rb	RRBb	RRbb	RrBb	Rrbb
rB	RrBB	RrBb	rrBB	rrBb
rb	RrBb	Rrbb	rrBb	rrbb

Red flowers with broad leaves -RRBB-1,

Red flowers with intermediate leaves - RRBb -2

Pink flowers with broad leaves RrBB-2

Pink flowers with intermediate leaves RrBb- 4

Red flowers with narrow leaves- RRbb- 1

Pink flowers with narrow leaves- Rrbb -2

White flowers with broad leaves- rrBB-1

White flowers with intermediate leaves- rrBb-2

white flowers with narrow leaves - rrbb- 1