1. 6d. Blood Typing
Chapter 7.1 & 7.2

2. Blood types
There are several different blood types a person can inherit
The possibilities: A+, A-, B+, B-, O+, O-, AB+, AB-

3. Blood types have 3 modes of inheritance
Blood type exhibits Codominance, Polygenic and Multiple Allele inheritance
Codominance
A is dominant and B is also dominant
Therefore is someone inherits and A and a B, their phenotype is AB
O is recessive to both A & B

4. Polygenic
When you inherit your alleles from your parents you get the following:
The “letter” A, B or O
AND
The Rh Factor + or – (+ is dominant, - is recessive)
Therefore, your blood type is polygenic because you have 2 sets of genotypes giving 1 phenotype
Example Blood type: A+

5. Multiple Allele Traits
This mode of inheritance is when you have more than 2 alleles in the gene pool
For example:
Sally has Blood type: AB
Bob has Blood type: O
* The Gene pool consists of A, B & O BUT you will only receive 2 of the 3 available. (Why? You only have 2 shoes)

6. Writing Blood Type genotypes
There are 2 ways you can write the blood types
Using the letter I/i indicates dominance
IAi or IAIA = blood type A
IBi or IBIB = blood type B
IAIB = Blood type AB
ii = Blood Type O OR
Not Using the letter I/i you need to remember dominance
AA or AO= blood type A
BB or BO = blood type B
AB = Blood type AB
OO= Blood Type O

7. Let’s Practice: IAIA IBi ii IAIB What is the phenotype for? Type A
Type B
Type O
Type AB

8. Let’s Practice Punnett Squares
Show a cross between IAi and IBIB
IA i IB
IAIB
IBi
IBi
IAIB

9. Let’s Practice more Punnett Squares
Gertrude has type AB- blood, and she has babies with Thomas who has type O+ blood (he is heterozygous for rh) What could their babies be?
Gertrude =
IAIB--
ii+-
Thomas =
IA-
IA-
IB-
IB- i+
IAi+-
IAi+-
IBi+-
IBi+- i+
IAi+-
IAi+-
IBi+-
IBi+-
IBi-- i-
IAi--
IAi--
IBi--
IAi--
IAi--
IBi--
IBi-- i-