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Pedigrees. It is a diagram that shows how a trait is inherited through several generations. Squares = males Circles = females Shaded = individual has the trait or condition Unshaded = individual does not have trait or condition horizontal line = marriage
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It is a diagram that shows how a traitis inherited through several generations. • Squares = males • Circles = females • Shaded = individualhas the trait or condition • Unshaded = individual does not have trait or condition • horizontal line = marriage • vertical line = offspring, arranged from left to right in order of birth • Roman numerals - label different generations What is a Pedigree? Sounds like a dog food.
By analyzing patterns of inheritance, biologists can learn about genetic diseases. • If a trait is autosomal, it willappear in both sexes equally and if it is sex-linked, it is usually seen only in males. • The major use of pedigree analysis is in clinical evaluation and counseling of patients with inherited abnormalities. Patterns of Inheritance
Pedigree for the Albino Trait • Pedigree for a Sex Linked Trait Human geneticists illustrate the inheritance of a gene within a family by using a pedigree chart.