In cats gene 1 specifies coat color allele B leads to black

In cats, gene 1 specifies coat color; allele B leads to black coat while allele b leads to chocolate coat color. Gene 2 can inhibit coat color: genotype cc leads to an albino cat while at least one copy of allele C allows the full color from gene 1 to be expressed. From the cross bbCc x BbCc, what fraction of the offspring are expected to be albino?

a. 8/16
b. 1/16
c. 4/16
d. 2/16
e. 3/16

Solution

The punnett square of dihybrid cross bbCC x BbCc is given below:

bb

Cc

Bb

Cc

bb

bbbb

Cbbc

Bbbb

Cbbc

Cc

Cbcb

CCcc

CBcb

CCcc

Bb

Bbbb

BCbc

BBbb

BCbc

Cc

Cbcb

CCcc

CBcb

CCcc

As the albino cat genotype is cc, in the above table out of 16, 4 has the genotype cc and so the answer is 4/16.