Topic 2: Extensions and Exceptions to Mendel's Laws of inheritance-PART ONE

DUE FRIDAY, MAY 7TH

Assignment ONE---Complete part 1 and 2

This session will will explore many of the "extensions and exceptions" to Mendel's Laws of inheritance.

Assignment 1: Who's baby is it?

Human blood type genetics provides another example of multiple gene inheritance. There are several genes that influence blood types, in particular, the ABO and Rh factor genes.

For the ABO gene, we can have A blood, B blood, AB blood or O blood.

For the Rh gene, we can have Rh+ or Rh-.

Taking these together, we can have A+, A-, B+, B-, AB+, AB-, O+, or O- blood.

The ABO gene also provides an example of codominance. There are three alleles for this gene: the A allele, the B allele, and the O allele. Both A and B alleles are dominant (so there are 2 forms of the dominant gene, the A form and the B form), while O is recessive. Thus, if a person inherits an A allele and a B allele, they would have AB blood.

The only way to have O blood is to inherit two O alleles (ii).

To begin this assignment, complete the following:

Sites to Visit:
How Stuff Works: Blood Types
http://health.howstuffworks.com/question593.htm

Blood Types Tutorial and Practice Problems
http://www.biology.arizona.edu/human_bio/problem_sets/blood_types/Intro.html

Blood Typing: See Introduction and Blood Typing game
http://www.nobel.se/medicine/educational/landsteiner/index.html

Part 1: Blood typing game answers
WHILE COMPLETING THE BLOOD TYPING GAME, ANSWER THE FOLLOWING QUESTIONS!!!
1) What is the bloodtype of the man with the purple mohawk?
2) What is the bloodtype of the red haired woman???
3) What is the bloodtype of the old balding man???


Part 2: Sample Blood-Typing Problems: (Complete the following)

A) Show the Punnett square of a cross between a man who is homozygous for A blood with a woman who is homozygous for B blood. Give the phenotype(s) and the ratios of the possible children.

B) Show the Punnett square of a cross between a man who is heterozygous for A blood with a woman who is heterozygous for B blood. Give the phenotype(s) and the ratios of the possible children.