1. (Where did you get your genes?)
Types of Dominance
(Where did you get your genes?)

2. Incomplete Dominance Neither trait is dominant over the over
Principle of Dominance does NOT apply!
Hybrid phenotype looks “in between” the two homozygous phenotypes

4. F2 Generation

6. Types of Dominance Incomplete Dominance
genotype: heterozygous (hybrid)
phenotype: the mix or “in between” of the two
parents
example: white flower x red flower  pink flowers

7. Codominance Neither trait is dominant over the over
Principle of Dominance does NOT apply!
Hybrid genotype displays phenotype where both P generation phenotypes can be seen

8. BB x WW

9. F1 cross (BW x BW)

10. TYPES OF DOMINANCE Codominance
offspring does not look like either parent
both alleles in the offspring are dominant
example: black cow x white cow  checkered (roan) cow

11. Multiple Alleles More than two allele possibilities exist
Ex: blood type
A, B, O

12. Multiple Alleles
More than two allele possibilities exist

13. Dad = type A blood Mom = type B blood
A & B are codominant
A & B are both dominant over O

14. blood type determined by the presence or absence of proteins on the surface of red blood cells
types: A, B, AB, O

15. Antigen on red blood cell
BLOOD TYPES
Phenotype
(blood type)
Genotype
Antigen on red blood cell
Safe Transfusions To
From A
AA or AO
A, AB
A,O B
BB or BO
B, AB
B, O AB
only AB
A and B
A, B, AB, O O
only O
none

17. Polygenic traits

19. Sex-linked traits 23 pairs of chromosomes 46 total
1st 22 pairs = “autosomes”
23d pair = sex chromosomes
XX = female XY = male
X & Y = “sex chromosomes”

20. Karyotype A picture of an organism’s chromosomes
Can be used to determine if there are genetic abnormalities

21. SEX-LINKED TRAITS controlled by genes located on sex chromosomes
usually found on the X (female) chromosome
female are usually carriers because they have XX
for X-linked traits, males pass the trait to their daughters not their sons…why?
examples: colorblindness, hemophilia

26. H = does not have hemophilia
h = hemophilia
Xh Y XH Xh