Mutations

Chromosomal Mutations Nondisjunction Result of errors in Meiosis Results in gametes with missing or extra chromosomes Examples: Downs Syndrome, Turner’s Syndrome, Kleinfelters Syndrome

Nondisjunction

Chromosomal Mutations Broken chromosomes Deletions = section of chromosome is lost during cell division Inversion = broken section of chromosome is reversed and reattached to the chromosome

Chromosomal Mutations Duplication = fragment attaches to its homologous chromosome Translocation = fragment attaches onto a nonhomologous chromosome

Sources of Genetic Variation Independent assortment Crossing over Mutations

Types of Mutations in Genes Point mutation Mutation in a single base pair

Types of Mutations in Genes Frame shift mutation Alters the entire amino acid sequence

Genetic Disorders Single gene defect Treatments Mutation in an allele (point mutation or frame shift) Examples: cystic fibrosis, sickle cell disease, Huntington’s Treatments Modify lifestyle Drug therapy Gene therapy

Genetic Disorder Diagnosis Fetal Screening Amniocentesis Ultrasound Newborn Screening Blood tests can screen for a few disorders (PKU) Gene Testing DNA tested to see if carrying a specific gene.

Pedigree Allows us to track traits and/or mutations among related individuals over many generations