Chapter 11 Complex Inheritance and Human Heredity

Presentation Focus Questions: 1.How can genetic patterns be analyzed to determine dominant or recessive inheritance patterns? 2.What are some examples of dominant and recessive disorders? 3.How can human pedigrees be constructed from genetic information? Chapter 11: Inheritance & Heredity

Genetic Disorders: A disease caused in whole or in part by a change in the DNA sequence away from the normal sequence. Causes: Gene mutation (single or multiple) Environmental Factors Chromosomal Damage Chapter 11: Inheritance & Heredity

Recessive Genetic Disorders: Only expressed when an individual is homozygous for that trait. Carrier Recessive disorder masked by Dominant trait. Individual “carries” genetic disorder, but is not expressed. Chapter 11: Inheritance & Heredity

Albinism: 1 in 17,000 No color in skin, hair, eyes Vision Problems No cure Visual rehabilitation Chapter 11: Inheritance & Heredity Cystic Fibrosis: 1 in 3,500 Excessive Mucous buildup Digestive / Respiratory Failure No cure Daily Cleaning of mucus from the lungs Recessive Genetic Disorders

Tay-Sachs Disease: 1 in 2500 Unable to breakdown Fatty Substances Mental Disabilities No cure / Treatment Death by age 5 Chapter 11: Inheritance & Heredity Galactosemia: 1 in 50,000 Unable to breakdown galactose Mental Disabilities / kidney failure No cure Restricted diet Recessive Genetic Disorders

Dominant Genetic Disorders: Individuals who do not possess disorder are homozygous recessive You only need to inherit 1 allele to have Dominant Disorder Chapter 11: Inheritance & Heredity Duchenne Muscular Dystrophy

Huntington’s Disease 1 in 10,000 Decline of mental / neurological function No cure or treatment Achondroplasia (Dwarfism) 1 in 25,000 Short arms / legs No cure or treatment Chapter 11: Inheritance & Heredity

Rare Genetic Disorders Chapter 11: Inheritance & Heredity Argyria Werewolf Syndrome Human Pappiloma Virus

Rare Genetic Disorders Chapter 11: Inheritance & Heredity Hutchinson-Gilfordprogeria Cutaneous Horns Fibrodysokasia Ossificans Progressiva

In small groups, discuss the following….. 1.How can rare recessive disorders occur in families after many generations of healthy individuals? 2.Why are recessive disorders more common than dominant disorders? Chapter 11: Inheritance & Heredity

How can we predict the chances of inheritance? Punnett Squares How can a family predict their chances of passing on a genetic disorder? Pedigree Chapter 11: Inheritance & Heredity

Pedigree Diagram that traces inheritance of a particular trait through generations A genetic “family tree” Chapter 11: Inheritance & Heredity

Pedigree “key” Chapter 11: Inheritance & Heredity Carrier (non Affected)

Chapter 11: Inheritance & Heredity Who has the genetic disorder?

Chapter 11: Inheritance & Heredity Dominant or Recessive? Recessive!

Chapter 11: Inheritance & Heredity Dominant or Recessive? Recessive!