1. Continuing Genetics DOMINANCE Unit 5: Mendelian Genetics

2. Independent Assortment
genes that are inherited separately do not influence the inheritance of others
Alleles segregate independently during meiosis
some go to one gamete and some to another

3. Types of Dominance Incomplete Dominance:
Offspring genotype is heterozygous (hybrid)
Phenotype is between two parents
In offspring, Dominant gene cannot fully inhibit the recessive
Ex: white flower x red flower = pink flowers

4. Offspring shows phenotype of neither parent Both alleles are dominant
Codominance:
Offspring shows phenotype of neither parent
Both alleles are dominant
Ex: black cow x white cow = checkered/spotted cow
Bay horse x white horse = roan horse

5. Multiple alleles: more than two alleles control a trait
Ex: height, hair color, eye color and blood type

6. Blood type inheritance
Blood type is determined by the presence or absence of proteins on surface of red blood cells
Blood types: A, B, AB and O
Phenotype (BLOOD TYPE)
GENOTYPE
ANTIGEN on red blood cell
SAFE TRANSFUSIONS TO
FROM A
 AA or AO  A
 A, AB
A, O B
BB or BO  B 
 B, AB
B, O AB
Only AB 
A & B 
 AB
A, B, AB, O O
 Only OO
None 
 A, B, AB, O

7. Sex-linked alleles controlled by genes located on sex chromosomes
Usually carried on X chromosome
Since females are XX, they are usually carriers of the trait
Since males are XY, they have a higher tendency for inheritance of trait

8. Sex-linked
If trait is X-linked: males pass it to all of their daughters, none to sons
If trait is X-linked: mothers have 50/50 chance of passing it to all of their children
Ex: colorblindness, hemophilia

9. Work the following Punnett Square:
Male: has Hemophilia (XhY)
Female: Carrier (XHXh)