Constructing pedigrees:
A pedigree chart is a diagram that shows the occurrence and appearance of a particular gene/ trait, including its ancestors from one generation to another. A pedigree is most commonly in the presentation of family information in the form of a simple/ readable chart. Pedigrees use a standardized set of symbols, squares represent males and circles represent females. It should be noted that pedigree construction is a family history, and as such details about an earlier generation may be uncertain as memories fade. Relationships in a pedigree are shown as a series of lines. Parents are connected by a horizontal line and a vertical line leads to their offspring. The offspring are connected by a horizontal sibship line and listed in birth order from left to right. If the offspring are twins then they will be connected by a triangle. If an offspring dies then its symbol will be crossed by a line. Analysis of the pedigree using the principles of Mendelian inheritance can determine whether a trait has a dominant or recessive pattern of inheritance.
This is an example of a basic pedigree: (autosomal, dominant)
This is an example of a basic pedigree: (autosomal, dominant)