PROBABILITY LAB
How does chance affect the
combination of alleles
Hypothesis
Which combination of beans (alleles) will occur must often?
____________________________________________
Procedure
Answer:
1.
2.
3.
Obtain one male bag and one female bag.
Make certain that there is 50 red and 50 white beans in each bag. These bags
represent the P1 generation.
What is the genotype of these parents
P1
: _______ x _______
4.
Use a Punnett square below to predict the ratio of Red/Red, White/White,
Red/White genoptypes combinations will be selected. Use ‘R’ to represent the Red
Bean phenotype. Use ‘W’ to represent the White Bean phenotype.
5.
6.
7.
Take one bean out of each bag and tally results in ‘Data’ section below.
Place the two gametes back in their respective parents’ bag.
Shake the bag again and repeat so you have 100 entries in your data.
Data Table
Beans
Group Tally Marks
Group Total
Class Total
R/R
R/W
W/W
Questions
1. Which genotype combination occurred most
often in the experiment?
2. If red is dominant and white is recessive,
how many plants have a dominant
phenotype?
3. How did your predicted results of selected
combinations compare with your actual
results?
4. Which of the ratios produced the closest
results, the ‘Group’ or the ‘Class’ totals?
5. What is the probability of selecting the same
color in a pair of alleles each time?
6. How does chance affect allele combination?