Bellwork: 4/15 Put your phone up  Week 4/15 - 4/19 Gary has Type A blood. Gary’s mom has Type O blood & her husband has blood Type AB. Gary thinks he looks more like his uncle Larry. Larry is homozygous for blood Type A. What are the chances the husband could be the father. What are the chances Larry could be the father?

Today: Bellwork Part 5 Notes Sex-Linked Traits Packet

Materials Unit Book Sex-Linked Traits Pkt

This Week: Monday: Pt. 5 Notes & Practice Tues/Wed: Sex-Link Quick Lab & Movie Thursday: Quiz, Pt. 6 Notes, & Practice Friday: Practice & White Board Practice

Next Week: Monday: Study Guide (maybe Kahoot) Tues/Wed: Test Thursday: Presentations Friday: Presentations

Homework Sex-Linked Traits Packet Genetics Project Unit 6 Test Due next class Genetics Project Due 4/24 at 11:59pm Unit 6 Test Period 4 & 6: April 23 Period 5 & 7: April 24

Unit VI: Mendelian Genetics

Part V: Sex-Linked Traits

Intro ?s Genetically, what determines whether a fetus is a boy or a girl? Who determines gender, Mom or Dad? Explain

Human Chromosomes Humans have 23 pairs of chromosomes 1-22 chromosome pairs are… Autosomal chromosomes (autosomes) Chromosomes not related to gender 23rd chromosome pair are the sex chromosomes XX=female XY=male

Human Chromosomes

Sex-Linked Disorders Most X-linked genes Have no homologous loci (positions on Y) Very few genes found on the Y chromosome Most genes on the Y chromosome associated with maleness More than 100 have now been mapped

Role of Father in Passing Sex-Linked Traits Father determines gender Donates Y chromosome to son Donates X chromosome to daughter Fathers cannot pass sex-linked traits to son because… He does not give him an X chromosome Males receive X chromosome from mother So the mother passes sex-linked traits to son

Role of Mother Pass sex-linked alleles (X) to both daughters and sons

Sex-Linked Traits More Common in Males…WHY? Females have fewer sex-linked disorders because… It only show up if homozygous recessive Females have two X chromosomes Males have only one X chromosome If they have one disorder allele, they have the disorder More common to have sex-linked disorders

Practice Problem Red-green color blindness is a sex-linked trait. The dominant allele, C, produces normal color vision. The recessive allele, c, produces red-green color blindness. If a man with normal color vision marries a color-blind woman, what is the chance of them having a color-blind son? A color blind daughter?

Common Sex-Linked Disorders Color Blindness Most commonly red-green color blindness X-linked recessive disorder Individuals with this color blindness see fewer than 25 colors Results from some or all of the receptors respond to red and green being weakened or absent

Common Sex-Linked Disorders Hemophilia A Causes lack of blood clotting X-linked recessive disorder Symptoms Tend to bruise easily Internal bleeding can cause problems with muscles & joints

Common Sex-Linked Disorders Duchenne Muscular Dystrophy Disease that results in the progressive weakening of skeletal muscles X-linked recessive disorder

Common Sex- Linked Disorders Fragile X Syndrome Attributed to autism and mental retardation Causes large protruding eyes, ears and an elongated face X-linked recessive disorder https://www.youtube.com/watch?v=bV6N1tLIPQA

Answer ?s in Note Guide