Answer :
Let's walk through the steps needed to calculate the frequency of the recessive allele given the population details.
1. Count the total number of chickens:
- Homozygous dominant: 45
- Heterozygous dominant: 30
- Recessive: 25
- Total chickens = 45 + 30 + 25 = 100
2. Calculate the total number of alleles in the population:
Each chicken has 2 alleles. Therefore, the total number of alleles = 2 total number of chickens = 2 100 = 200 alleles.
3. Calculate the number of recessive alleles:
- Each homozygous dominant chicken (45) has 0 recessive alleles.
- Each heterozygous dominant chicken (30) has 1 recessive allele.
- Each recessive chicken (25) has 2 recessive alleles.
- Total recessive alleles = (0 45) + (1 30) + (2 * 25) = 0 + 30 + 50 = 80 recessive alleles.
4. Calculate the frequency of the recessive allele:
The frequency of the recessive allele is given by the proportion of recessive alleles to the total number of alleles.
- Frequency of the recessive allele = [tex]\(\frac{\text{Number of recessive alleles}}{\text{Total number of alleles}} = \frac{80}{200}\)[/tex].
Thus, the correct expression to calculate the frequency of the recessive allele is:
[tex]\[ B. \frac{80}{200} \][/tex]
Therefore, the correct answer is (B) [tex]\(\frac{80}{200}\)[/tex].
1. Count the total number of chickens:
- Homozygous dominant: 45
- Heterozygous dominant: 30
- Recessive: 25
- Total chickens = 45 + 30 + 25 = 100
2. Calculate the total number of alleles in the population:
Each chicken has 2 alleles. Therefore, the total number of alleles = 2 total number of chickens = 2 100 = 200 alleles.
3. Calculate the number of recessive alleles:
- Each homozygous dominant chicken (45) has 0 recessive alleles.
- Each heterozygous dominant chicken (30) has 1 recessive allele.
- Each recessive chicken (25) has 2 recessive alleles.
- Total recessive alleles = (0 45) + (1 30) + (2 * 25) = 0 + 30 + 50 = 80 recessive alleles.
4. Calculate the frequency of the recessive allele:
The frequency of the recessive allele is given by the proportion of recessive alleles to the total number of alleles.
- Frequency of the recessive allele = [tex]\(\frac{\text{Number of recessive alleles}}{\text{Total number of alleles}} = \frac{80}{200}\)[/tex].
Thus, the correct expression to calculate the frequency of the recessive allele is:
[tex]\[ B. \frac{80}{200} \][/tex]
Therefore, the correct answer is (B) [tex]\(\frac{80}{200}\)[/tex].