Thread: How should I read pedigrees to determine the inheritance patters?

I would appreciate it if you could explain or show me a link or website...Any kind of help is appreciated.

In a pedigree chart, generations are represented by Roman numerals. Each person in each generation is numbered.
Males are represented by a square and females by a circle.
A horizontal line connecting a male and female is called a marriage line.
Vertical lines represent children.
Children on the vertical line are always placed from left to right, with the child on the left being the oldest.


Determining Genotypes:
If we look at a specific trait (earlobe shape ) there are two general shapes of earlobes. The first being individuals with the dominant, free ear lobes (E) and the recessive, attached ear lobes (e). Individuals on a pedigree chart that have unshaded symbols have at least one dominant gene, and show the dominant trait.

Rules one must follow to predict genotype:

Any person on a pedigree chart that has a shaded symbol must be assigned two (2) recessive genes.
Place lower case letters under the person's symbol.
Any person on a pedigree chart that has an unshaded symbol must be assigned a dominant gene.
Place a capital letter under the person's symbol.
To determine the second gene for persons who show a dominant trait a Punnett square must be used.