A rough-coated male guinea pig is crossed with a homozygous smooth-coated female (rr). Their offspring are rough-coated and smooth-coated in a 1:1 ratio. Use a Punnett square to calculate the genotype of the male parent.
2007-05-08 09:50:46 · 3 answers · asked by ? 3 in Science & Mathematics ➔ Biology
Rough-coated male is either RR or Rr.
Smooth-coated female is rr.
Try the two crosses to see which genotype is right for the male.
If male is RR: Cross RR x rr.
F1 are all Rr; all rough. That can't be it.
If male is Rr: Cross Rr x rr.
Gametes from first parent go on the left side of the square: R and r.
Gametes from second parent go on the top of the square: r and r.
First row of boxes in the square: Rr and Rr.
Second row of boxes in the square: rr and rr.
F1 are 2 rough: 2 smooth. This reduces to 1 rough: 1 smooth.
The male must have been Rr.
2007-05-08 09:58:57 · answer #1 · answered by ecolink 7 · 0⤊ 0⤋
I'm assuming that rough coat is the dominant allele here, right? The genotype of the male guinea pig would be Rr, heterozygous for rough coat.
2007-05-08 17:07:31 · answer #2 · answered by smiley5671 2 · 0⤊ 0⤋
The father is Rr
2007-05-08 16:57:57 · answer #3 · answered by Anonymous · 0⤊ 0⤋