Question

in guinea pigs, black hair color (b) is dominant to brown hair color (b). if two guinea pigs who are heterozygous for black hair mate, what is the probability that they could have a guinea pig that has brown fur?

50%

0%

75%

25%

Explanation:

Step1: Determine Genotypes

Heterozygous black guinea pigs have genotype \( Bb \).

Step2: Set Up Punnett Square

Parents: \( Bb \times Bb \).
Punnett square:

	B	b
b	Bb	bb

Step3: Analyze Offspring Genotypes

• \( BB \): black (homozygous dominant)
• \( Bb \): black (heterozygous)
• \( bb \): brown (homozygous recessive)

Step4: Calculate Probability

Out of 4 possible offspring genotypes, 1 is \( bb \) (brown). So probability is \( \frac{1}{4} = 25\% \).

Answer:

25% (the option with "25%")