1. Human Heredity

2. 1) Autosomes 2) Sex chromosomes
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 XX O Only 1 sex chromosome is present.
*Associated with underdeveloped ovaries, short stature, webbed neck, and broad chest.
*Individuals are sterile, and lack 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) Genetic disorders
Harmful effects produced by mutated genes, most are recessive and few are lethal
Example: sickle cell anemia

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

12. 7) 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

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

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

15. Carrier Mom
XHXh
XHXH XHXh XHY XhY

16. Royal Hemophilia

17. Sex linkage & calico cats

18. Polydactyly (multiple fingers and toes)