Question

Suppose you are looking at a group of 50 individuals. 45 are homozygous dominant and 5 are homozygous recessive. How many heterozyous individuals would you expect there to be in a group of 100 individuals.

Hint: you will first need to calculate the allele frequencies then use that to determine the number of indivudals that would be heterozygous.

The answer is 18, but how do I get there.

Answer 1

Answer 2

To determine the number of heterozygous individuals in a group of 100 individuals, you can follow these steps:

1. Calculate the allele frequencies:

• Let's denote the dominant allele as "A" and the recessive allele as "a".

• In the given group of 50 individuals, 45 are homozygous dominant (AA) and 5 are homozygous recessive (aa).

• The total number of alleles in the population is 2 * 50 = 100.

• The frequency of the dominant allele (A) can be calculated as (2 * number of AA individuals) / total number of alleles = (2 * 45) / 100 = 0.9.

• The frequency of the recessive allele (a) can be calculated as (2 * number of aa individuals) / total number of alleles = (2 * 5) / 100 = 0.1.

2. Calculate the probability of being heterozygous:

• The probability of an individual being heterozygous (Aa) can be calculated as 2 * frequency of allele A * frequency of allele a = 2 * 0.9 * 0.1 = 0.18.

3. Determine the number of heterozygous individuals in a group of 100:

• Multiply the probability of being heterozygous by the total number of individuals: 0.18 * 100 = 18.

Therefore, you would expect there to be 18 heterozygous individuals in a group of 100 individuals.