Determine whether the trait is dominant or recessive. If the trait is dominant, one of the parents must have the trait. Dominant traits will not skip a generation. If the trait is recessive, neither parent is required to have the trait since they can be heterozygous.
Determine if the chart shows an autosomal or sex-linked (usually X-linked) trait. For example, in X-linked recessive traits, males are much more commonly affected than females. In autosomal traits, both males and females are equally likely to be affected (usually in equal proportions).
Pedigrees of autosomal recessive traits will have equal frequencies of affected males and females, whereas pedigrees X-linked recessive traits will show that most of the affected individuals are male.
Step-by-step explanation:
If the trait is dominant, one of the parents must have the trait. Dominant traits will not skip a generation. If the trait is recessive, neither parent is required to have the trait since they can be heterozygous.A pedigree is a chart which shows the inheritance of a trait over several generations. From studying a pedigree, scientists can determine if a trait is sex-linked or autosoma If an individual has that trait, their symbol on the pedigree will be shaded in. If they have no widow's peak, their symbol will not be shaded in because having no widow's peak is recessive. Certain traits like colorblindness are located on the X or Y chromosome and are called sex-linked 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 Autosomal recessive patterns manifest by skipping generations as the affected are usually children of unaffected carriers. It is also common to see affected individuals with unaffected offspring. ... The most common situation of an autosomal recessive disease occurs when the parents are each carrier or heterozygous (Dd)
