1. Sex - Linked Genes and Nondisjunction Disorders

2. Human Chromosomes One Human Chromosome has 46 chromosomes

3. Karyotype A picture of all chromosomes from an individual’s cells.

4. Autosomal Chromosomes 44 out of the 46 chromosomes

5. Sex Chromosomes 2 of the 46 chromosomes (determines an individual's sex) XX XY Female Male

6. Sex - Linked Genes Definition: Genes found on the Sex Chromosomes

7. Sex - Linked Genetic Disorders Mostly found on the X chromosome Sex - Linked Genetic Disorders Colorblindness Hemophilia Duchenne Muscular Dystrophy

8. Colorblindness Characteristics: Unable to distinguish certain colors (most commonly red and green) Mostly occurs in males Treatment: none Life Expectancy: normal

9. Can You See the Number 12?

10. Can you see the number 7?

11. What Colorblind People See NormalColorblind

12. What Colorblind People See NormalColorblind

13. Hemophilia Characteristics: Protein necessary for normal blood clotting is missing Can bleed to death from minor cuts or can suffer internal bleeding from bumps or bruises Treatment: Injections of normal clotting proteins Medical Complications: Forming antibodies against normal clotting proteins Life Expectancy: Normal if they keep up with their injections

14. An individual with hemophilia after he banged his knee

15. Duchenne Muscular Dystrophy Cause: Absence of dystrophin a protein that helps keep muscle cells intact Characteristics: Primarily affects males around the age of 3 Progressive weakening and loss of skeletal and voluntary muscle Treatment: Physical and Occupational therapy for range of motion and adaptive equipment NO CURE Life Expectancy: 20s

16. Individual with Muscular Dystrophy

17. Down Syndrome “Trisomy 21” Cause: Three copies of chromosome 21 Characteristics: Low muscle tone Flat facial profile Upward slant to eyes Small ears Protruding tongue Mild to moderate intellectual impairment Treatment: Physical, occupational, speech therapy Medical Problems: Congenital heart defects Hearing loss Vision problems Life expectancy: Average age is in the mid 50s

18. Down Syndrome

19. Down Syndrome Clip http://www.youtube.com/watch?v=-_- P4t2jR1g

20. Nondisjunction Disorders Failure of chromosome pairs to separate properly during cell division Disorders: Klinefelter’s Syndrome Down Syndrome Edward’s Syndrome Turner Syndrome

21. Klinefelter Syndrome XXY Cause: Nondisjunction Characteristics: Only affects MALES Usually don’t develop facial, underarm or pubic hair, don’t develop sperm and develop more breast tissue than normal due to decreased amounts of testosterone Learning disabilities Treatment: Testosterone injections Life Expectancy: Normal life span

22. An Indivdual with Klinefelter’s Syndrome

23. Karyotype of Klinefelter’s Syndrome

24. Edward’s Syndrome “Trisomy 18” Cause: 3 copies of chromosome 18 due to translocation Characteristics: Clenched hands Rocker bottom feet Abnormally shaped head Small head and jaw Abnormalities of organs Treatment: Supportive care Life Expectancy: Majority only live to one month

25. Physical Deformities in Edward’s Syndrome Clenched FistRocker Foot

26. Turner Syndrome Cause: Have only one X chromosome or a one full X chromosome and one partial X chromosome Characteristics: Only affects girls Will not go through all the changes associated with puberty Infertile Webbed neck Low hair line at the back of the neck Average height 4’7’’ Treatment: Growth hormone Estrogen injections Life Expectancy: normal

27. Karotype of Turner Syndrome

28. Turner Syndrome (Webbed Neck and Low Hair Line)