Expert: Walter Hintz - 4/13/2010

Question
in guinea pigs, the allele for rough coat (R) is dominant to the allele for smooth coat (r), and the allele for black fur (B) is dominat to th allele for white fur (b). if two guinea pigs that are heterozygous for rough coat, and heterozygous for black fur are mated, what are the possible genotypes and phenotypes? show in punnett square please.

Answer
Hi Yvette; My policy when I get genetics problems like this to to set up the punnett square and partially finish it. Then I ask the student to finish it. I will not do all your work for you. If you have questions I will help you

   Cross     RrBb     x     RrBb

     RB       Rb      rB      rb

RB  RRBB     RRBb    RrBB    RrBb

Rb

rB

rb

Now you complete the square. If you cannot finish let me know
The Mendelian phenotype ratio here is  9:3:3:1