Answer:
A) The frequency of the dominant allele, C ![= 0.4376](https://tex.z-dn.net/?f=%3D%200.4376)
B) frequency of the heterozygous genotype, Cc ![= 0.2461](https://tex.z-dn.net/?f=%3D%200.2461)
Explanation:
Given -
Curly hair, C, is the dominant allele, and straight hair, c, is the recessive allele
Number of students with curly hair is ![37](https://tex.z-dn.net/?f=37)
Thus frequency of genotype "CC"
![= q^{2} = \frac{37}{117} \\= 0.3162](https://tex.z-dn.net/?f=%3D%20q%5E%7B2%7D%20%3D%20%5Cfrac%7B37%7D%7B117%7D%20%5C%5C%3D%200.3162)
Thus, frequency of allele "q"
![= \sqrt{0.3162} \\= 0.5623](https://tex.z-dn.net/?f=%3D%20%5Csqrt%7B0.3162%7D%20%5C%5C%3D%200.5623)
As per Hardy Weinberg's first equation-
![p+q=1](https://tex.z-dn.net/?f=p%2Bq%3D1)
Substituting the value of q, we get -
![p+0.5623=1\\p= 0.4376](https://tex.z-dn.net/?f=p%2B0.5623%3D1%5C%5Cp%3D%200.4376)
As per Hardy Weinberg's second equation -
![p^2+q^2+2pq=1\\](https://tex.z-dn.net/?f=p%5E2%2Bq%5E2%2B2pq%3D1%5C%5C)
Substituting the values of "p" and "q" we get -
![0.4376^{2} + 0.3162+2pq = 1\\2pq = 0.2461\\](https://tex.z-dn.net/?f=0.4376%5E%7B2%7D%20%2B%200.3162%2B2pq%20%3D%201%5C%5C2pq%20%3D%200.2461%5C%5C)
Hence,
A) The frequency of the dominant allele, C ![= 0.4376](https://tex.z-dn.net/?f=%3D%200.4376)
B) frequency of the heterozygous genotype, Cc ![= 0.2461](https://tex.z-dn.net/?f=%3D%200.2461)