Biology
Read the Lab 12 procedures and watch the online Hardy-Weinberg video (https://youtu.be/xPkOAnK20kw and posted on BlackBoard), then complete this assignment prior to lab.
1. The Hardy-Weinberg Theorem states…
2. What are the five key assumptions that are necessary for the H-W Theorem to be valid?
3. Write the Hardy-Weinberg equation:
4. Dominant allele “R” has a frequency (p) of 0.45 in a particular gene pool. Calculate the following showing all your work and using the proper variables for each value (e.g. p, q, p^{2}, q^{2}, 2pg).
a. The frequency of allele “r” in that same gene pool?
b. The proportion of the population that has the genotype RR.
c. The proportion of the population that has the genotype Rr.
d. The proportion of the population that has the genotype rr.
5. If 17% of a population displays the recessive trait for Disease B, what are the frequencies of the recessive allele “b” and the dominant allele “B” in the gene pool?
6. You perform an experiment where you allow a large population of fruit flies to mate randomly. The parental generation had 30% homozygous recessive genotypes. The F_{1} generation consisted of 100 flies, 40 of which displayed the recessive trait. Calculate the expected values for each phenotype assuming Hardy-Weinberg equilibrium, then fill in the table below and use the Chi-Square test instructions document (posted online) to compare your calculated X^{2} value with the tabulated X^{2} value for a P-value of 0.05.
# of dominant phenotype individuals | # of recessive phenotype individuals | |
Observed value (o) | ||
Expected value (e) | ||
Deviation (o – e) = d | ||
d^{2} | ||
d^{2}/e | ||
Calculated Chi-square (X^{2}) = Σd^{2}/e | ||
Degrees of Freedom | ||
Tabulated X^{2} value at P=0.05
(from X^{2} instructions document) |
a. According to your analysis above, are the observed proportion of genotypes in the F_{1} generation the same, or significantly different, than those expected according to the H-W theorem?
b. If you allowed your F_{1} generation to mate, what would you expect the frequency of the recessive allele (q) to be in the F_{2} generation, assuming the H-W theorem applies?