Following Traits in Families Pedigrees Following Traits in Families

Pedigree: A diagram that follows the traits through a family Circles and Squares represent people Shaded circles/squares represent people that have the trait “being followed” A half-shaded symbol represents a ‘carrier’

Pedigree analysis Pedigree analysis reveals Mendelian patterns in human inheritance data mapped on a family tree = male = female = male w/ trait = female w/ trait

Simple pedigree analysis What’s the likely inheritance pattern? Simple pedigree analysis 1 2 3 4 5 6 1 2 3 4 5 6

Genetic counseling Pedigree can help us understand the past & predict the future Thousands of genetic disorders are inherited as simple recessive traits from benign conditions to deadly diseases albinism cystic fibrosis Tay sachs sickle cell anemia PKU

Douglas and Lauren have three children, two girls and a boy. This line indicates a family Douglas Lauren Children are left to right, oldest to youngest

Douglas has brown hair. We will ‘follow’ this trait Douglas has brown hair. We will ‘follow’ this trait. Show the brown hair trait by shading in the circle Douglas Lauren

Lauren has blonde hair so we do not shade her in. Douglas Lauren

Their oldest daughter and youngest son have brown hair also. Douglas Lauren

Shade them in as well. Douglas Lauren

You try: Ryan and Jessica have two children. Richard and Sarah. Ryan does not have dimples, but Jessica does. Richard has dimples but Sarah does not. Jessica’s parents both have dimples Jessica has a sister who does not have dimples Follow the dimples trait

1) Blue Eyes Brandon is trying to figure out why he has blue eyes when his mother father and brother all have brown eyes. Draw a pedigree for Brandon and his mother, father and brother. Looking at family pictures he finds out that is father’s father had blue eyes. Later he also finds out that his mother’s mother has blue eyes. Follow the blue eyes trait

2) Juan and Jamie have one daughter, Anna 2) Juan and Jamie have one daughter, Anna. All of them have hitchhiker’s thumb. Anna marries a man named Adam with a straight thumb. They have two sons the oldest has hitchhikers thumb the youngest does not. Follow the hitchhiker’s thumb trait

3) April and Anthony are brother and sister they both have brown hair, their parents both have brown hair Their mother’s father has blonde hair Their father’s mother has brown hair. Their mother’s sister has blonde hair. Their aunt got married and had two blonde haired children with a blonde haired man, one boy and one girl. Follow the blonde hair trait

4) Bob and Jane have 8 kids. Three daughters, then three sons, then 2 more daughters. Bob is blood type A. Jane is blood type O. Child #1, 3, 7, 8 all have blood type A. The oldest daughter gets married to a man with blood type O They have 3 girls, all with blood type A. Write the blood type genotypes for each of the individuals

Is the trait followed below: -Dominant. -Recessive. -Sex-Linked Is the trait followed below: -Dominant? -Recessive? -Sex-Linked? Explain how you know!