Answer
1. The Punnett Square for two parents with normal skin color having an albino baby would look like this:
| | A | a |
|---|---|---|
| A | AA | Aa |
| a | Aa | aa |
Both Tiffany and Joe must be carriers of the recessive allele (a) for their baby to be albino. This means that they each have one dominant allele (A) and one recessive allele (a). When they have children, there is a 25% chance that both parents will pass on the recessive allele, resulting in an albino child.
2. Joe is partially correct. The chance of having an albino child is 25% for each pregnancy, regardless of whether they have already had an albino child. However, the chance of having three non-albino children in a row is not guaranteed. Each pregnancy is independent of the previous ones, so the chance of having a non-albino child is still 75% for each pregnancy.