Pedigrees

Nothing flashy, but a quick review of inheritance followed by a silent tutorial on how to use/read a pedigree. Remember a few vocabulary that we discussed:

Autosomal chromosome– this is referring to your body chromosomes
Sex chromosome – this is referring to your sex chromosomes (X & Y for humans)
Dominant – this is referring to an allele for a trait that can mask a recessive trait (typically shows in every generation)
Recessive – this is referring to an allele for a trait that is masked by a dominant trait (typically skips a generation)

Gregor Mendel & Punnett Squares

The following video clip reviews how to create and fill out Punnett squares. Now we like to use letters that represent what we are looking at and they should always be the same for dominant and recessive. When we write heterozygous allele pairs, they should always have the dominant allele written first.

If you want to go a little furthur and review some of the concepts from today (before we make it more complicated next class) watch the following lesson.