Biology Name:
Jones Period: Date:
The Hardy-Weinberg Principle
In a field, there is a population of snapdragons. Some are red (FRFR), some are white (FWFW), and some are pink (FRFW). Flower petal color in snapdragons is controlled by incomplete dominance. In this activity, you will be following this population through several generations and noting whether or not evolution is occurring and relating this to the Hardy-Weinberg Principle.
1. What different alleles are present in this gene pool?
2. What different phenotypes are present in this population?
3. In your own words, explain genetic equilibrium.
4. What five conditions must be met in order for a population to reach genetic equilibrium?
5. Generation #1: There are ten flowers in this population with the following genotypes:
FRFR, FRFR, FRFR, FRFR, FRFR, FRFW, FRFW, FRFW, FRFW, FRFW
Use this data to calculate the following frequencies for this gene pool:
Allele Frequencies Phenotypic Frequencies
FR: Red:
White:
FW: Pink:
6. These snapdragons are crossed and their offspring is Generation #2. Mating between the snapdragons was completely random and no phenotype was favorable over another. This new generation consists of six red, three pink, and one white flower. Write out the genotypes of these flowers in the space below:
Use this date to calculate the following frequencies for this gene pool:
Allele Frequencies Phenotypic Frequencies
FR: Red:
White:
FW: Pink:
a. Have either of these frequencies changed from Generation #1 to #2?
b. Has the population truly evolved? Why or why not?
7. Five more snapdragons are brought into the population. This new larger population is called Generation #3. This generation consists of eleven red, three pink, and one white flower. Write out the genotypes for this generation in the space below:
Use this date to calculate the following frequencies for this gene pool:
Allele Frequencies Phenotypic Frequencies
FR: Red:
White:
FW: Pink:
a. Have either of these frequencies changed from Generation #2 to #3?
b. If so, which part of the Hardy-Weinberg Principle was violated? Explain.
8. Generation #4 is produced by the intervention of a plant breeder. Thirteen red and one pink are produced. Determine the genotypes and calculate the frequencies in the space below.
a. Have either of these frequencies changed from Generation #3 to #4?
b. If so, which part of the Hardy-Weinberg Principle was violated? Explain.
9. Generation #5 has thirteen red, one pink and includes one orange snapdragon (No need to write the genotypes of this one,…think!).
a. Have either of these frequencies changed from Generation #4 to #5?
b. If so, which part of the Hardy-Weinberg Principle was violated? Explain.
10. Generation #6 is just two pink snapdragons and their offspring, Generation #7, is only 5 white snapdragons. Write out the genotypes and calculate the allele frequencies for both Generation #6 and Generation #7.
Generation #6 Generation #7
FR: FR:
FW: FW:
a. Have either of these frequencies changed from Generation #6 to #7?
b. If so, which part of the Hardy-Weinberg Principle was violated? Explain.