1. Karyotypes

2. How karyotypes are made… http://www.youtube.com/watch?v=dPk_V1KkMuU&safety_mode=true&per sist_safety_mode=1&safe=active

3. Humans have 46 chromosomes in 23 pairs  1 st – 22 nd = autosomes  23 rd = sex chromosomes

4. Karyotype Karyotype = chart of paired chromosomes

5. Sex Determination  1 st – 22 nd = autosomes  23 rd = sex chromosomes (determine the sex) XX = femaleXY = male Female Male

6. Male or female? Female!

7. Male or female? Male!

8. What do karyotypes allow us to observe? 1.Gender or sex of the individual 2.Chromosomal disorders

9. How can you tell nondisjunction has occurred?

10. Chromosomal Disorders, caused by nondisjunction, are “read” using karyotypes

11. Chromosomal Disorders Chromosomal Disorders= diseases that result from an abnormality in chromosome number – Caused by NONDISJUNCTION (failure of chromosomes to separate properly during meiosis)

12. Nondisjunction

13. Karyotypes allow us to see Chromosomal Disorders 3 Chromosomal Disorders: 1.Down Syndrome 2.Klinefelter Syndrome 3.Turner Syndrome

14. Down Syndrome AKA “Trisomy 21” 3 chromosomes of the 21 st pair Causes: mental and physical disability

15. Down Syndrome

16. Kleinfelter’s Syndrome Kleinfelter syndrome = trisomy 23 (sex chromosomes) Causes: small testicles, reduced fertility in males

17. Klinefelter’s Syndrome

18. Turner Syndrome Missing X chromosome Causes: non working ovaries; male-like stature Females only

20. Turner Syndrome

21. What causes chromosomal disorders?