Question

1. in cats, the gene for calico (multicolored) cats is codominant. females that receive a b and an r gene are both black and orange (tortoiseshell) males can only be black or orange.

show the cross of a female tortoiseshell cat $x^bLXB0y$
how many offspring will be:
female / calico ____
female / black ____
male / black ____
male / orange ____

Explanation:

Step1: Identify parent gametes

Female ($X^B X^R$) gametes: $X^B$, $X^R$
Male ($X^B Y$) gametes: $X^B$, $Y$

Step2: Create Punnett square

$$\begin{array}{|c|c|c|} \hline & X^B & Y \\ \hline X^B & X^B X^B & X^B Y \\ \hline X^R & X^B X^R & X^R Y \\ \hline \end{array}$$

Step3: Count offspring genotypes/phenotypes

• $X^B X^R$: Female/Calico (1)
• $X^B X^B$: Female/Black (1)
• $X^B Y$: Male/Black (1)
• $X^R Y$: Male/Orange (1)

Answer:

Female / Calico 1
Female / Black 1
Male / Black 1
Male / Orange 1