1. Unit 4--Genetics Chapter 14 Human Heredity

2. 1) Autosomes –all the chromosomes except the sex chromosomes (in humans, there are 22 pair) 2) Sex chromosomes –The sex-determining chromosomes, the X & Y

3. 3) Karyotype –Pictures of paired human chromosomes arranged by size, used to identify abnormalities in fetuses –Cells from an amniotic fluid sample are cultured, stained & photographed

6. 4) Nondisjunction –Failure of chromosomes to separate –May cause a variety of birth defects, including trisomy 21 or Down syndrome

7. Turner’s syndrome XX O Only 1 sex chromosome is present. Turner syndrome is associated with underdeveloped ovaries, short stature, webbed neck, and broad chest. Individuals are sterile, and lack expected secondary sexual characteristics. Mental retardation typically not evident.

8. Klinefelter’s syndrome

9. 5) Pedigree5) Pedigree –Chart showing family history of a trait –Solid light = homozygous dominant, solid dark = homozygous recessive, half-circle = heterozygous

10. 6) Blood groups % of U.S. population

11. Serum Universal recipient Universal donor

12. 7) Genetic disorders –Harmful effects produced by mutated genes, most are recessive and few are lethal –Example: sickle cell anemia

13. Normal, with malarial resistance Same as parents ; normal, no resistance; sickle-cell anemia

14. 8) Sex-linked traits –A recessive gene on the X chromosome –Examples: color-blindness & hemophilia –Genotypes:Phenotypes: – X N Ynormal male – X n Ycolorblind – X N X N normal female – X N X n carrier female – X n X n colorblind

15. normal vision “weak red” “weak green”

16. Phenotypes??? Cross of carrier female & normal male XNXN XnXn XNXN Y XNXNXNXN XNXnXNXn XNYXNYXnYXnY

17. XHXhXHXh X H X H X H X h X H Y X h Y Carrier Mom

18. Royal Hemophilia

19. Sex linkage & calico cats

20. Polydactyly (multiple fingers and toes)