A horse population has the following distribution of genotypes for coat color.

\begin{tabular}{|c|c|c|c|}
\hline
Genotype & [tex]$B B$[/tex] & [tex]$B b$[/tex] & [tex]$b b$[/tex] \\
\hline
Number of individuals & 35 & 40 & 25 \\
\hline
Phenotype & Black & Gray & Brown \\
\hline
\end{tabular}

What is the frequency of the [tex]$B B$[/tex] genotype?

A. 0.40
B. 0.35
C. 1.00
D. 0.25



Answer :

To determine the frequency of the [tex]\( BB \)[/tex] genotype in a horse population, we need to follow these steps:

1. Calculate the Total Number of Individuals:
First, find the total number of individuals in the population by adding the number of individuals for each genotype.
[tex]\[ \text{Total individuals} = \text{Number of } BB + \text{Number of } Bb + \text{Number of } bb \][/tex]
Given data:
[tex]\[ \text{Number of } BB = 35 \][/tex]
[tex]\[ \text{Number of } Bb = 40 \][/tex]
[tex]\[ \text{Number of } bb = 25 \][/tex]
[tex]\[ \text{Total individuals} = 35 + 40 + 25 = 100 \][/tex]

2. Determine the Number of [tex]\( BB \)[/tex] Genotype Individuals:
From the given data, the number of individuals with the [tex]\( BB \)[/tex] genotype is 35.

3. Calculate the Frequency of the [tex]\( BB \)[/tex] Genotype:
The frequency of a specific genotype is found by dividing the number of individuals with that genotype by the total number of individuals in the population.
[tex]\[ \text{Frequency of } BB = \frac{\text{Number of } BB}{\text{Total individuals}} \][/tex]
Substituting the values we have:
[tex]\[ \text{Frequency of } BB = \frac{35}{100} = 0.35 \][/tex]

Therefore, the frequency of the [tex]\( BB \)[/tex] genotype is [tex]\( \boxed{0.35} \)[/tex].

The correct answer is:
B. 0.35