Unit 4--Genetics

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 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 . XX XX O

8. Klinefelter’s syndrome

9. 5) 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: XNY normal male XnY colorblind XNXN normal female XNXn carrier female XnXn colorblind

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

16. Cross of carrier female & normal male Xn XN XN XNXN XNXn Y XNY XnY Phenotypes???

17. Carrier Mom XHXh XHXH XHXh XHY XhY

18. Royal Hemophilia

19. Sex linkage & calico cats

20. Polydactyly(multiple fingers and toes)