For each pedigree shown,

Identify which simple pattern of hereditary transmission (autosomal dominant, autosomal recessive, X-linked dominant, or X-linked recessive) is most likely to have occurred. Give genotypes for individuals involved in transmitting the trait. 

Key Concepts

Pedigree Analysis

Pedigree analysis is a diagrammatic method used to trace the inheritance of traits through generations in a family. It helps identify patterns of inheritance by mapping out relationships and phenotypes of individuals. Understanding how traits are passed on allows geneticists to determine whether a trait is likely to be autosomal or sex-linked, and whether it is dominant or recessive.

Patterns of Inheritance

Patterns of inheritance refer to the predictable ways in which traits are transmitted from parents to offspring. The main patterns include autosomal dominant, where only one copy of the allele is needed for the trait to manifest, and autosomal recessive, where two copies are required. X-linked inheritance involves genes located on the X chromosome, with X-linked dominant traits appearing in both sexes, while X-linked recessive traits are more commonly expressed in males.

Genotype and Phenotype

Genotype refers to the genetic constitution of an individual, specifically the alleles they carry for a particular gene, while phenotype is the observable expression of those genes. In pedigree analysis, determining the genotypes of individuals helps predict the likelihood of trait transmission and expression in future generations. Understanding the relationship between genotype and phenotype is crucial for accurately identifying inheritance patterns.