1. Biology and Sex Chromosomal Sex Chromosomal Anomalies

2. KEY CONCEPTS Chromosomal Sex The Basics: 46 Chromosomes, Two Sex Chromosomes, X’s And Y’s Andosperm and Gynosperm The Problematic X Chromosome and Sex-Linked Traits Chromosomal Anomalies Errors in cell division lead to extra or missing chromosomes Ø)Turner’s Syndrome (X Ø) Trisomy X Syndrome (XXX) Klinefelter’s Syndrome (XXY or even XXXY) Supernumerary Y Syndrome (XYY)

3. OvumSperm Each contributes 23 chromosomes for a total of 46 Always an X An X or a Y

4. X Chromosome Y Chromosome

5. XX - Female XY - Male

6. OvumSperm Each contributes 23 chromosomes for a total of 46 Always an X An X or a Y Y-AndospermX-Gynosperm

7. XX - Female XY - Male THE PROBLEMATIC X CHROMOSOME Pathological Sex-Linked Traits Hemophilia Hemophilia Color Blindness Muscular Dystrophy

8. KEY CONCEPTS Chromosomal Sex The Basics: 46 Chromosomes, Two Sex Chromosomes, X’s And Y’s Andosperm and Gynosperm The Problematic X Chromosome and Sex-Linked Traits Chromosomal Abnormalities Errors in cell division lead to extra or missing chromosomes Ø)Turner’s Syndrome (X Ø) Trisomy X Syndrome (XXX) Klinefelter’s Syndrome (XXY or even XXXY) Supernumerary Y Syndrome (XYY)

9. XX - Female XY - Male

10. Trisomy X SyndromeTurner’sSyndrome In the absence of a “Y” chromosome, these are females.

11. Supernumerary Y Syndrome Klinefelter’s Syndrome In the presence of a “Y” chromosome, these are males. They are “Pseudo-hermaphrodites”