310 likes | 747 Views
Pedigrees and Karyotypes. Pedigree. A chart that shows the presence or absence of a trait according to the relationships within a family across generations. A square represents a male. A circle represents a female. A vertical line and a bracket connect the parents to their children.
E N D
Pedigree • A chart that shows the presence or absence of a trait according to the relationships within a family across generations A square represents a male. A circle represents a female. A vertical line and a bracket connect the parents to their children. A horizontal line connecting a male and female represents a marriage. A half-shaded circle or square indicates that a person is a carrier of the trait. A circle or square that is not shaded indicates that a person neither expresses the trait nor is a carrier of the trait. A completely shaded circle or square indicates that a person expresses the trait.
Modes of Inheritance • Autosomal Dominant • Ex Achondroplasia Dwarfism, Huntington’s Disease, Inherited colon & breast cancer, hypercholesterolemia • Autosomal Recessive • Ex Sickle Cell Disease, Cysic Fibrosis, Phenylketonuria (PKU), Recessive blindness, Tay Sachs
Modes of Inheritance • X-linked Dominant • Ex Hypophosphatemic rickets, Rett Syndrome, Incontinentiapigmenti (lethal in males), congenital generalized hypertrichosis (wolf man syndrome) • X-linked Recessive • Ex Dushene Muscular Dystrophy, hemophilia, color blindness
Autosomal Dominant • Transmitted directly from one generation to the next. • Males and Females affected equally • NEVER SKIPS A GENERATION • Never any carriers
Autosomal Recessive • Only expressed when in homozygous form • Males and females affected equally • May skip many generations before showing up • ¼ chance being affected when carriers mate
X-linked Dominant • Females affected more frequently • Daughters of affected males : 100% chance & sons: unaffected • Offspring of affected females : 50% chance
X-linked Recessive • Males affected more frequently because they only have one X chromosome • Typical transmission from carrier female
X-linked Recessive Continued • Sometimes carriers are not depicted on the pedigree
What Mode of Inheritance? Cystic Fibrosis
What Mode of Inheritance Huntington’s Disease
What Mode of Inheritance? Hypertrichosis
What Mode of Inheritance? Sickle Cell Anemia
What Mode of Inheritance? Duchenne Muscular Dystrophy
What Mode of Inheritance? Tay-Sachs
Definition A karyotype is the characteristic chromosome match (or complement) of a eukaryote species