Name_________________________________________
Blood Type Analysis
Non-Mendelian Genetics
CW
54
Sometimes traits are not as simple and dominant or recessive. While there are many examples of
these we will investigate just a few.
(1) Incomplete and Codominance (page 92 in Cells and Heredity)
(2) Multiple alleles (page 113 in Cells and Heredity)
Normal Dominant/Recessive Mendelian Genetics
1) If Red was dominant to White show the cross for RR x rr
However, in carnations and snap dragons we see that red and white flowers make pink offspring.
This is called Incomplete
Dominance.
2) In your own words try to describe what incomplete dominance
means.
Pink
White
Red
Another example is the Camellia flower. A red flow and a white
flower make offspring that with both red and white petals.
This is called Codominance
3) In your own words try to describe what codominance means.
Red and White
4) In all of the flower examples above how many different alleles were there? ___________________
(If you don’t remember what alleles, look at your foldable.)
5) What are the allele options for the flowers? _____________________ or ________________________
6) What were the phenotype possibilities for the normal dominant and recessive trait?
7) What were the phenotype possibilities for the incomplete dominant trait?
8) What were the phenotype possibilities for the codominant trait?
Multiple Alleles
Sometimes there are more than just 2 allele options for a trait. Blood types are a good example of this.
In humans (and most primates) there are three allele options that are possible: A, B and O.
9) What are the alleles possible for blood types : _____________, _______________, or ______________.
10)Which allele appears to be recessive? _______________
11)Which two alleles appear to be codominant? ______________ and ______________
12)We say that the genotype AO gives a phenotype of Type A . Fill in the genotype/phenotype chart
below for blood types.
Genotype
Phenotype
AA
AO
BB
Type B
Type AB
Drawing
13)What does it mean if we say a trait has multiple alleles?
14)No matter what, how many alleles are present in a given cell at one time?
Type O