Kolff Biology
Corn Dihybrid Genetics Investigation
Name: ___________________
Prelab Questions
1.
What is probability?
2. Why do actual and expected results differ?
3. Suppose we flipped 100 coins and got 58 heads. How many would we expect? _______
We calculate the expected number of heads by multiplying the total number of flips by the
probability of getting heads. Applying this to genetics, we can calculate the expected number of
each phenotype of offspring.
Draw a Punnett square to cross Aa x Aa, and write the probability for each genotype of offspring.
The offspring of this cross were: 25 AA, 69 Aa, and 26 aa. How many would we expect in each
category?
4.
What two traits are we investigating on the ears of corn for this lab? What are the different
versions of these traits?