Respuesta :
Assuming you mean to type:
"In humans, the allele for dimples (D) is dominant to the allele for no dimples (d). at another gene locus, the allele for broad eyebrows (B) is dominant to the allele for broad eyebrows (b)."
Man: Heterozygous for both genes means DdBb
Woman: no dimples, and heterozygous for slender eye-brows means ddBb
Punnett Square
DB Db dB db
dB DdBB DdBb ddBB ddBb
dB DdBB DdBb ddBB ddBb
db DdBb Ddbb ddBb ddbb
db DdBb Ddbb ddBb ddbb
Interpretation: anywhere that has a capital letter has the dominant trait.
Dimples+Broad eyebrows : 6 cases out of 16 (3/8=37.5%)
Dimples+slender eyebrows: 2 cases out of 16 (1/8=12.5%)
No dimples+Broad eyebrows: 6 cases out of 16 (3/8=37.5%)
No dimples+slender eyebrows: 2 cases out of 16 (1/8=12.5%)
Answer:
Genotype of offspring are –
DdBB – 2
DdBb – 4
ddBB -2
ddBb – 4
Ddbb – 2
ddbb-2
Phenotype –
Dimple & broad eyebrow- 6 (6/16)
Dimple & slender eyebrow- 2 (2/16)
No dimple & broad eyebrow- 6(6/16)
No dimple & slender eyebrow - 2(2/16)
Explanation:
Given -
Allele for dimples (D) is dominant to the allele for no dimples (d)
Allele for broad eyebrows (B) is dominant to the allele for slender eyebrows (b)
Male is heterozygous to both the traits. His genotype would be DdBb
woman who has no dimples and who is heterozygous at the gene locus controlling eyebrow width. Her genotype would be ddBb
Cross between the two i.e DdBb and ddBb gives the following offspring
DdBb and ddBb
DB Db dB db
dB DdBB DdBb ddBB ddBb
dB DdBB DdBb ddBB ddBb
db DdBb Ddbb ddBb ddbb
db DdBb Ddbb ddBb ddbb
Genotype of offspring are –
DdBB – 2
DdBb – 4
ddBB -2
ddBb – 4
Ddbb – 2
ddbb-2
Phenotype –
Dimple & broad eyebrow- 6 (6/16)
Dimple & slender eyebrow- 2 (2/16)
No dimple & broad eyebrow- 6(6/16)
No dimple & slender eyebrow - 2(2/16)
