Question

You discover a certain species of weed growing in soil contaminated with toxic PCBs, and later determine that the PCB resistance is due to a single dominant allele.

If 45% of the seeds from a randomly mating population of resistant weeds will germinate in contaminated soil, what is the frequency of the PCB-resistance allele?

Answer 1

The frequency of the PCB-resistance allele can be calculated using the Hardy-Weinberg equation. In a population of randomly mating individuals, the frequency of the dominant allele (p) can be determined by taking the square root of the percentage of resistant seeds (45%).

Step-by-step explanation:

The frequency of the PCB-resistance allele can be calculated using the Hardy-Weinberg equation. In a population of randomly mating individuals, the frequency of the dominant allele (p) can be determined by taking the square root of the percentage of resistant seeds (45%).

So, p = sqrt(0.45) = 0.67.

Since the resistance allele is dominant, the frequency of the recessive allele (q) can be calculated as q = 1 - p = 1 - 0.67 = 0.33.

Therefore, the frequency of the PCB-resistance allele is 0.67, or 67%.