How are individuals identified in a pedigree?
If the offspring is still born or aborted it is represented by a small triangle. Each generation is identified by a Roman numeral (I, II, III, and so on), and each individual within the same generation is identified by an Arabic numeral (1, 2, 3, and so on).
What is an individual in a pedigree?
A pedigree chart displays a family tree, and shows the members of the family who are affected by a genetic trait. … – a Roman Numeral, which stands for the generation in the family, – a Digit, which stands for the individual within the generation. (For instance, The female at the upper left is individual I-1.)
What are the 4 modes of inheritance?
Several basic modes of inheritance exist for single-gene disorders: autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive. However, not all genetic conditions will follow these patterns, and other rare forms of inheritance such as mitochondrial inheritance exist.
What does a circle represent in a pedigree?
In a pedigree, a circle represents a female, and a square represents a male. A filled-in circle or square shows that the individual has the trait being studied. The horizontal line that connects a circle and a square represents a marriage.
Who is the youngest in a pedigree?
General guidelines: It is helpful to start in the middle of the page when drawing a pedigree. Male partners are to the left of female partners. Siblings are drawn from oldest to youngest with the oldest listed on the left and the youngest on the right.