3.20

• Family pedigrees are shown like a tree diagrams with a symbol representing male and another symbol representing female. (For example square is male and circle is female)
• If these symbols are colored/filled in it shows that the person is affected by a disease that may or may not be passed on to the younger generations
• By using methods of trial and error we are able to eliminate and find out which gene caused the disease the recessive or the dominant.
• This is done by taking a sample from the family pedigree and testing the hypothesis for both dominant and recessive gene.