1/29/2013

Do you know what a Punnet Square is? Well, if you don't, here's a blog post all about it! Punnet Squares are used to determine the genotype of the offspring of two parents. In my science classroom, we have done a lot of problems with Punnet Squares. They are not that difficult to understand once you get the hang of it. The first step you need to do when you use a Punnet Square is determine both of the parent's genotype. Once you get that, you put one genotype on top of the square, and one genotype on the side of the square. Then you start to cross and get the genotype of the offspring.
One of my science worksheets had to deal with creating Punnet Squares. The problem was given to us and we created a Punnet Square to show our work. For example, one of the problems said, "Bob is homozygous for black hair, and his girlfriend also has black hair but she is heterozygous, what is the chance of them having a baby with black hair?" We would put both of the genotypes on the square and solve for the answer. It would be a 100% chance of have a baby with black hair.