Question

PLEASE HELP ME!!!! I am stuck.

The frequency of tasters and nontasters of PTC varies among populations. (Answer ALL questions)
- In population A, 94 percent of people are tasters (an autosomal dominant trait)
and 6 percent are nontasters.
- In population B, tasters are 75 percent and nontasters 25 percent.
- In population C, tasters are 91 percent and nontasters are 9 percent.

1. Calculate the frequency of the dominant (T) allele for PTC tasting in population A.
2. Calculate the frequency of the recessive (t) allele for nontasting in population A.
3. Calculate the frequency of the dominant (T) allele for PTC tasting in population B.
4. Calculate the frequency of the recessive (t) allele for nontasting in population B.
5. Calculate the frequency of the dominant (T) allele for PTC tasting in population C.
6. Calculate the frequency of the recessive (t) allele for nontasting in population C.
7. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population A.
8. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population A.
9. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population A.
10. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population B.
11. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population B.
12. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population B.
13. Assuming that Hardy-Weinberg conditions apply, determine the TT frequency in population C.
14. Assuming that Hardy-Weinberg conditions apply, determine the Tt frequency in population C.
15. Assuming that Hardy-Weinberg conditions apply, determine the tt frequency in population C.

Answer 1

The Hardy-Weinberg principle allows calculation of allele frequencies from phenotypic proportions in a population. In population A, the frequency of the recessive allele for PTC nontasting can be calculated from the nontaster percentage, then used to infer the dominant allele frequency and genotype frequencies.

Step-by-step explanation:

The Hardy-Weinberg principle provides a framework to understand the genetic structure of a population in equilibrium. Using it, we can calculate allele and genotype frequencies. The dominant allele frequency, p, and the recessive allele frequency, q, for PTC tasting can be inferred following the Hardy-Weinberg principle, where p + q = 1 and the genotype frequencies are p² (homozygous dominant), 2pq (heterozygous), and q² (homozygous recessive).

For population A, the nontasters' percentage, 6%, is equivalent to the homozygous recessive phenotype (tt), which is q². Therefore, q is the square root of 0.06, which is approximately 0.245. To find p, subtract q from 1, giving us about 0.755. The frequencies of TT (p²), Tt (2pq), and tt (q²) can be calculated using these values of p and q and the equations mentioned above.

Similar calculations apply to populations B and C, where the frequency of nontasters would be q² and we could derive p and q from there. Then, we would again use the Hardy-Weinberg equations to find the frequencies for TT, Tt, and tt genotypes within those populations.