To solve the problem, we need to fill in the missing data in the table and perform the necessary calculations. Let's break down the steps:
Given:
- Tasters frequency = \( p^2 + 2pq = 0.5 \)
- Non-tasters frequency = \( q^2 = 0.25 \)
From \( q^2 = 0.25 \), we can find \( q \):
\[ q = \sqrt{0.25} = 0.5 \]
Using \( p + q = 1 \):
\[ p = 1 - q = 1 - 0.5 = 0.5 \]
Using the allele frequencies \( p = 0.5 \) and \( q = 0.5 \), we can calculate the expected genotype frequencies:
- \( p^2 = (0.5)^2 = 0.25 \)
- \( 2pq = 2 \times 0.5 \times 0.5 = 0.5 \)
- \( q^2 = (0.5)^2 = 0.25 \)
The total number of individuals in BIO 340 is the sum of tasters and non-tasters:
\[ \text{Total} = 225 + 75 = 300 \]
Using the frequencies, calculate the expected counts:
- Expected tasters count = \( (p^2 + 2pq) \times \text{Total} = 0.5 \times 300 = 150 \)
- Expected non-tasters count = \( q^2 \times \text{Total} = 0.25 \times 300 = 75 \)
For the USA population, we have:
- Tasters frequency = 0.25
- Non-tasters frequency is missing.
Since \( p + q = 1 \), and assuming the same allele frequencies apply:
- \( q^2 = 0.25 \) (as given for BIO 340)
- Therefore, the non-tasters frequency for the USA is also 0.25.
To perform a chi-square analysis, we need to compare observed and expected counts for BIO 340:
Observed counts:
- Tasters: 225
- Non-tasters: 75
Expected counts:
- Tasters: 150
- Non-tasters: 75
Chi-square formula:
\[ \chi^2 = \sum \frac{(O - E)^2}{E} \]
Calculations:
- For tasters: \( \frac{(225 - 150)^2}{150} = \frac{75^2}{150} = \frac{5625}{150} = 37.50 \)
- For non-tasters: \( \frac{(75 - 75)^2}{75} = 0 \)
Total chi-square value:
\[ \chi^2 = 37.50 + 0 = 37.50 \]
- Allele frequencies for BIO 340: \( p = 0.5 \), \( q = 0.5 \)
- Expected counts for BIO 340: Tasters = 150, Non-tasters = 75
- USA non-tasters frequency: 0.25
- Chi-square value for BIO 340: 37.50
This completes the analysis and fills in the missing data in the table.