1. Ch. 10.5: Sex-Linked Traits Genes located on the X or Y chromosome XX = Female; XY = Male Objectives: 1.Explain how sex-linked genes produce different inheritance patterns in males and females. 2.Explain why most sex-linked disorders are more common in males. Vocab: sex-linked gene

2. X vs. Y More genes on X Male karyotype Female karyotype X: more than just genes for sex traits.

3. Thomas Hunt Morgan & Fruit Flies Discovers sex-linked traits. Recessive white eyes more common in MALE fruit flies. Females have to be homozygous recessive to have white eyes. Males only need one recessive allele for trait.

4. Sex-linked genes affect MALES more than females. Females can be carriers X N X n Males will express trait with just one allele, X n Y. Females have to be homozygous recessive to express trait.

5. Sex-Linked Disorders  Color-blindness  Hemophelia  Baldness  Fragile X  Versions of Muscular Dystrophy These are recessive disorders. There are dominant disorders that are more prevalent in females.

6. Color-blindness

7. Hemophelia Prevents blood clots. Without clotting factors (proteins), you can bleed to death.