Hello everyone ( : Today I would like to talk about Pedigree analysis. We all have been born with certain traits and using a pedigree we can determine where our certain traits came from and how we may pass them on. This is a chart that shows the symbols in a pedigree chart that will be useful for you to look at-



Now, I would like to show you some of the ways traits are inherited.

1. Autosomal Dominant traits- Females and males are both able to have the trait. The trait will not skip generations, and effected children will have at least one affected parent. Here's an example-


2. Now we have autosomal recessive traits. This is when both males and females are equally likely to get the trait, but the traits do skip generations. Children can be affected, but not have affected parents. So the parents are carriers. Cystic fibrosis is a autosomal recessive disease.


3. X linked recessive traits are found mainly in men. This trait is passed from mother to son with the mother being a carrier. This trait will skip one or more generations.


4. X linked dominant- This mode of inheritance effects twice as many girls than boys and the traits don't skip generations. The affected mother will pass her trait on to half of her children usually and girls and boys are both capable of getting the trait. All daughters of an affected dad will be affected.


5. And now we have the Y linked traits. Obviously only males are affected because they are XY and girls are XX. Affected fathers always pass this on to their son's and it will not skip generations.


I would highly recommend going to this website and doing the activity-

http://learn.genetics.utah.edu/content/addiction/genetics/pi.html

It helps you understand pedigrees and how traits are passed through generations and I thought it was pretty fun ( :