1. Non-Mendelian Genetics
Some traits don’t follow the simple dominant/recessive rules that Mendel first applied to genetics.
Traits can be controlled by more than one gene.
Some alleles are neither dominant nor recessive.

2. Incomplete Dominance Four O’Clock Plants
One allele is not completely dominant over another.
The heterozygous phenotype is a blending of the two homozygous phenotypes.
Ex: RR (RED) x R’R’ (WHITE)= PINK (RR’)
Four O’Clock Plants
Curly x Straight= Wavy hair texture

4. CoDominance Two alleles are both expressed as a dominant phenotype.
Coat color in cows
RR: Red, WW: White, RW: Roan, white with red spots (NOT pink!)

5. Roan Animals Show Codominance

7. Multiple-Allele Series
Codominance
More than two choices of alleles are present for a trait
ABO blood type has three alleles:
ABO Blood types:
If both A and B are present, type is AB
Neither is recessive
Individuals can be type A, B, AB, or O (recessive)

8. What is blood made up of? The red blood cells The white blood cells
contain hemoglobin.
Red blood cells transport O2 and CO2 to and from body tissues.
The white blood cells
fight infection.
The platelets
help the blood to clot
The plasma
Fluid which contains salts and various kinds of proteins.

9. Determining Blood Type
                                                                                             
(not actual shape or size of antigens)
                                                                                             
(not actual shape or size of antigens)
                                                                                             
(not actual shape or size of antigens)
Determining Blood Type
Protein molecules found on the surface of RBC’s and in the blood plasma determine the blood type of an individual.
Antigens are located on the surface of the red blood cells
Antibodies are in the blood plasma.

10. Human Blood Types

11. What are the different blood groups?
Blood group A (IA, IA ), (IA, i) have A antigens on the surface of red blood cells and B antibodies in blood plasma.
Blood group B (IB, IB ), (IB, i)
have B antigens on the surface of red blood cells and A antibodies in blood plasma.

12. What are the different blood groups?
Blood group AB (IA, IB ) have both A and B antigens on the surface of red blood cells
and no A or B antibodies in blood plasma.
Universal receivers
Blood group O (i, i) have neither A or B antigens on the surface of red blood cells but have both A and B antibodies in blood plasma. Universal donors

13. Rh Factor Refers to another antigen on red blood cells
Dominant trait is to have the antigen
Rh+
Recessive trait is not to have it
Rh-
A person with Rh- blood will produce antibodies to Rh+ blood
Can be a problem in pregnancy

15. Review Males have an X and a Y chromosome
Females have two X chromosomes
These chromosomes determine sex, so genes located on these chromosomes are known as sex-linked genes.

16. The X chromosome is much larger than the Y- it carries more genes than the Y chromosome.
Disorders that are sex-linked are much more common in males, because they would only need 1 recessive allele to have the trait; rather than the two recessive alleles the females need.

17. Practice Problems EXAMPLES!!
A woman who is heterozygous for normal vision marries a man who is colorblind. What are the chances of them having a son or daughter who is colorblind?

18. In fruit flies, the gene for eye color is sex-linked
In fruit flies, the gene for eye color is sex-linked. The allele for red eyes if dominant, while the allele for white eyes is recessive. A white eyed male is mated with a heterozygous red-eyed female. Show the punnet square and list the genotypic and phenotypic ratios for this cross.