1. HEREDITY: A Different Set of Rules
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HEREDITY: A Different Set of Rules

2. Incomplete Dominance
the heterozygous genotype shows a “blending” of traits

3. AA’ x AA’ 2 1 1

4. Codominance
there is more than one dominant allele – requires 2 different uppercase letters
Both alleles expressed equally – both traits show at the same time

5. B B
W W BW
Roan Horse

7. Checkered Chicken

8. sickle-cell anemia most common of African descent
hemoglobin differs by one amino acid
becomes “sickle” shaped
reduces oxygen carrying capacity

10. Multiple Alleles
a trait controlled by more than two alleles

11. Mutations

12. Chromosome number: monosomy, trisomy
nondisjunction – homologous chromosomes don’t separate during meiosis
monosomy, trisomy

14. Most common: trisomy 21 (down syndrome) - autosome XO, XXY - sex
recognized by a karyotype – picture of chromosomes

18. DNA Mutations

19. Point mutation