Question

In a population of rabbits, the brown fur color (B) is dominant to the white fur color (b). If a heterozygous brown rabbit is crossed with a homozygous white rabbit, what is the probability of their offspring having brown fur?

• A.
• B.
• C.
• D.

Hint:

In a dominant-recessive inheritance pattern, the dominant allele will mask the effect of the recessive allele. Use a Punnett square to determine the genetic ratios of offspring.

Answer 1

The Correct Option is A

To determine the probability of the offspring having brown fur, we need to understand the genetics of fur color in rabbits. Brown fur (B) is dominant, and white fur (b) is recessive.
- A heterozygous brown rabbit has the genotype \( Bb \), where \( B \) is the dominant brown allele and \( b \) is the recessive white allele.
- A homozygous white rabbit has the genotype \( bb \), since both alleles for white fur are recessive.
When a heterozygous brown rabbit (\( Bb \)) is crossed with a homozygous white rabbit (\( bb \)), we can use a Punnett square to determine the possible genotypes of the offspring.
The parents are:
- \( Bb \) (brown rabbit)
- \( bb \) (white rabbit)
From this Punnett square, we can see that: - 50% of the offspring will have the genotype \( Bb \) (brown fur), - 50% of the offspring will have the genotype \( bb \) (white fur).
Since brown fur is dominant, any offspring with at least one \( B \) allele will have brown fur. Thus, 50% of the offspring will have brown fur.
Thus, the probability of the offspring having brown fur is \( 50\% \).