In poultry, two genes, R and P, control the shape of the comb on the head. The following genotype/phenotype relationship applies to these two genes: R- P- animals have a 'walnut' comb; R- pp animals have a 'rose' comb; rr P- animals have a 'pea' comb; rr pp animals have a 'single' comb. What will the comb phenotypes of the progeny be for a cross of rr PP X rr Pp animals

Respuesta :

Answer:

100% of the progeny will have a pea comb, rrP-

Explanation:

Available data:

  • two genes, R and P, control the shape of the comb on the head
  • R- P- animals have a 'walnut' comb
  • R- pp animals have a 'rose' comb
  • rr P- animals have a 'pea' comb
  • rr pp animals have a 'single' comb

Cross:

Parentals)      rrPP          x        rrPp

Gametes) rP, rP, rP, rP        rP, rP, rp, rp

Punnett square)     rP     rP      rP      rP

                    rP    rrPP   rrPP   rrPP  rrPP

                    rP    rrPP   rrPP   rrPP  rrPP

                    rp    rrPp   rrPp   rrPp   rrPp

                    rp    rrPp   rrPp   rrPp   rrPp

F1) Genotype

  • 8/16 = 1/2 = 50% of the progeny will be rrPP
  • 8/16 = 1/2 = 50% of the progeny will be rrPp

    Phenotype

    16/16 = 100% of the progeny will have a pea comb