In a population of guinea pigs, short hair is dominant to long hair. If 25 percent of a breeder’s guinea pigs has long hair, what is the frequency of the recessive allele (q)? 5 percent 15 percent 25 percent 50 percent

In this scenario, the frequency of the recessive allele (\(q\)) can be determined using the Hardy-Weinberg equilibrium equation:

\[ p^2 + 2pq + q^2 = 1 \]

where:

- \( p \) is the frequency of the dominant allele (in this case, for short hair),

- \( q \) is the frequency of the recessive allele (in this case, for long hair),

- \( p^2 \) is the frequency of individuals with two dominant alleles (homozygous dominant),

- \( 2pq \) is the frequency of individuals with one dominant and one recessive allele (heterozygous), and

- \( q^2 \) is the frequency of individuals with two recessive alleles (homozygous recessive).

Given that 25 percent of the guinea pigs have long hair (\( q^2 \)), we can set up the equation:

\[ q^2 = 0.25 \]

Now, to find \( q \), take the square root of both sides:

\[ q = \sqrt{0.25} = 0.5 \]

So, the frequency of the recessive allele (\( q \)) is \( 50 \) percent.