The ability to taste PTC is due to a single dominate allele "T". You sampled 215 individuals in biology, and
determined that 150 could detect the bitter taste of PTC and 65 could not. Calculate the frequency of the
heterozygous genotype.
a
50%
b
34%
c
72%
d
17%
b. 34%
To calculate the frequency of the heterozygous genotype, we need to determine the frequency of individuals who are homozygous dominant (TT) and homozygous recessive (tt) first.
From the information provided:
- 150 individuals could detect the taste of PTC (TT or Tt)
- 65 individuals could not detect the taste of PTC (tt)
Therefore, the frequency of the homozygous dominant genotype (TT) = 150 - 65 = 85 individuals
The frequency of the homozygous recessive genotype (tt) = 65 individuals
Total individuals sampled = 215
Frequency of homozygous dominant genotype (TT) = 85/215 = 0.3953 or 39.53%
Frequency of homozygous recessive genotype (tt) = 65/215 = 0.3023 or 30.23%
Now, to calculate the frequency of the heterozygous genotype:
Frequency of heterozygous genotype (Tt) = 1 - (frequency of homozygous dominant + frequency of homozygous recessive)
Frequency of heterozygous genotype (Tt) = 1 - (0.3953 + 0.3023) = 0.3024 or 30.24%
Therefore, the frequency of the heterozygous genotype is approximately 30.24%, which is closest to option b. 34%.