Respuesta :
Taking; H+ = allele for the presence of horns
H- = allele for hornlessness
Since H+ is recessive in females, the horned female parents must be H+H+. The hornless male is H-H- because the absence of horns is recessive in males. Then their F1 progeny must be all heterozygous H+H-. An intercross of the F1 would produce both male and female progeny in the ration of 1 H+H+, 2 H+H-, and 1 H-H-. Additionally, remembering that H+ is recessive in females, we would expect a ratio of 3:1 hornless to horned females.
H- = allele for hornlessness
Since H+ is recessive in females, the horned female parents must be H+H+. The hornless male is H-H- because the absence of horns is recessive in males. Then their F1 progeny must be all heterozygous H+H-. An intercross of the F1 would produce both male and female progeny in the ration of 1 H+H+, 2 H+H-, and 1 H-H-. Additionally, remembering that H+ is recessive in females, we would expect a ratio of 3:1 hornless to horned females.
Answer:
[tex]\frac{1}{4}[/tex]of the f2 females will have horns
Explanation:
Let the "presence of horn" trait be represented by "H"
and the "absence of horn" trait be represented by "h"
Given presence of horn is a dominant trait in males and recessive trait in females.
F1 Cross -
Horned female genotype - HH
Hornless male genotype - hh
HH * hh
Hh, Hh, Hh, Hh
F2 Cross
Hh * Hh
HH, Hh, Hh, hh
Only one female will have horns
[tex]\frac{1}{4}[/tex]of the f2 females will have horns
