You Mate a Squash with the Genotype AAbb with a Squash

Essay

You mate a squash with the genotype AAbb with a squash with the genotype aaBB.The resulting F₁ squash are all AaBb.After mating two F₁ squash,you obtain an F₂ generation of squash as follows: ("-" = either allele)
$$\begin{array} { l r } A -\quad B - & 5 \\A - \quad bb & 45 \\a a\quad B - & 47 \\aa \quad bb & 3 \\\hline \text { Total } & 100\end{array}$$
a)What does this tell you about assortment of the two traits?
b)What could account for the distribution obtained?