Question

How do I set up or the punnet square or what do I put on the left side?

Answer 1

In this case, we have a heterozygous dihybrid cross, where we are combining hair color (Black=B, White=b) and hair type (Rough=R, Smooth=r), so for the punnet square we need to obtain first the gametes (combinations)

Parents: BbRr x BbRr

Obtaining gametes

`\begin{gathered} B\begin{cases}R=BR \\ r=Br\end{cases} \\ b\begin{cases}R=bR \\ r=br\end{cases} \end{gathered}`

Now we can proceed to do the punnet square