Bellringer Where are genes located (hint: chromosomal theory of inheritance)? What is genetic linkage?

Learning Target Describe the purpose of a pedigree and use a pedigree to track a trait or disorder within a family.

Pedigrees

This is a Pedigree Chart showing colorblindness in a family Why are more males than females colorblind?

A Pedigree Chart Is Like A Family Tree  A Pedigree Chart Is Like A Family Tree A Pedigree Chart: Shows genetic connections among individuals in a family. Has Standardized symbols May be used to estimate probability and patterns of inheritance over generations

Basic Symbols of A Pedigree 

A Few Extra

Tracing the “Royal Disease” Hemophilia Hemophilia is an X-linked recessive disorder characterized by the inability to properly form blood clots Became known as the “Royal disease” because it spread to the royal families of Europe through the descendents of Queen Victoria Became known as “curse of the Coburgs”

Queen Victoria’s Pedigree

What’s the likely MODE OF TRANSMISSION? Autosomal Dominant Autosomal Recessive Sex-Linked Recessive   Look for the “male pattern”, female carriers

What’s the likely MODE OF TRANSMISSION?  Autosomal Dominant Autosomal Recessive Sex-Linked Recessive  In every generation, no carriers

What’s the likely MODE OF TRANSMISSION?   Autosomal Dominant Autosomal Recessive Sex-Linked Recessive Usually skips generations But not always!*

Let’s build our own pedigree!  Debbie married David and had three children, Darren, Dawn, and Derek. David, Darren and Derek discovered they have muscular dystrophy. Derek married Didi and had two children, Denise and Destiny. Denise also has muscular dystrophy and married Dirk. They had two children, Dee and Deven. Dee has muscular dystrophy. 1) Draw the pedigree, showing the relationships between family members

Let’s build our own pedigree!  Debbie married David and had three children, Darren, Dawn, and Derek. David, Darren and Derek discovered they have muscular dystrophy. Derek married Didi and had two children, Denise and Destiny. Denise also has muscular dystrophy and married Dirk. They had two children, Dee and Deven. Dee has muscular dystrophy. 2) Identify the phenotype of each family member (affected, unaffected, carrier, etc.)

Let’s build our own pedigree!  Debbie married David and had three children, Darren, Dawn, and Derek. David, Darren and Derek discovered they have muscular dystrophy. Derek married Didi and had two children, Denise and Destiny. Denise also has muscular dystrophy and married Dirk. They had two children, Dee and Deven. Dee has muscular dystrophy. 3) Determine the genotype of each family member and the mode of transmission Mm mm mm Mm mm Mm mm Mm mm Autosomal Dominant Mm mm