Question

In cats, the gene for Calico (multicolored) cats is an x-linked trait that is
CODOMINANT. Females that receive a "B" and an "R" gene have black and orange
splotches on white coats. Males can only be black or orange, but never calico.
A female calico's genotype is XBXR
Cross a female calico cat with a black male. (Complete a Punnett square)
What are the results of the cross?
25% Black and male, 0% Calico Male, 25% Calico female
50% Black and male, 50% Calico female.
50% Orange and male, 50% Female Black

Answer 1

Answer:

Considering the whole progeny (100%), there will be

• 25% Black male kittens, XBY
• 0% Calico Male kittens
• 25% Calico female kittens, XBXR

Explanation:

Available data:

• The gene for Calico (multicolored) cats is an x-linked trait and codominant
• Calico Females receive a "B" and an "R" gene, and have black and orange splotches on white coats. Their genotype is XBXR.
• Males can only be black or orange, but never calico. Their genotype is XBY and XRY

Cross: a female calico cat with a black male

Parentals)   XBXR    x    XBY

Gametes)  XB  XR       XB   Y

Punnett square)    XB        XR

                   XB   XBXB   XBXR

                    Y      XBY      XRY  

F1) Among the whole progeny:

•     2/4 = 50%  will be black (female XBXB and male XBY)
•     1/4  = 25% will be Calico (female XBXR)
•     1/4  = 25% will be Orange (male XRY)  

   Among females:

•    1/2 = 50% of females will be black, XBXB
•    1/2 = 50% of females will be Calico, XBXR

   Among males:

•    1/2 = 50% of males will be black, XBY
•    1/2 = 50% of males will be orange, XRY