Chapter 4.7, Problem 6A

To determine

The percent chance that the child is immune to poison ivy from the given Punnett square (column-wise father and row-wise mother) for genetic combinations of two parents and explain their meaning if P is the dominant gene whose one copy is enough for a person to be immune to poison ivy and p is the recessive gene whose two copies are required for a person to be susceptible to poison ivy.

$\begin{array}{ccc}& P& p\\ P& PP& Pp\\ p& pP& pp\end{array}$