Question

Brown rabbits have the genotype BB or Bb. White rabbits have the genotype bb. If two brown rabbits, with the genotypes seen in the Punnett square above, have baby rabbits, what is the probability that the baby rabbits will also be brown?
Responses

A 25%25%

B 50%50%

C 75%75%

D 100%

Answer 1

To determine the probability of the baby rabbits being brown when two brown rabbits are crossed, we need to consider their possible genotypes.

Assuming one brown rabbit has the genotype BB and the other has Bb, we can use a Punnett square to find the probabilities of the offspring's genotypes:

1. **Parent Genotypes:**
- Parent 1: BB
- Parent 2: Bb

2. **Punnett Square:**

| | B | B |
|------|------|------|
| B | BB | BB |
| b | Bb | Bb |

3. **Offspring Genotypes:**
- BB: 2 (which are brown)
- Bb: 2 (which are also brown)

4. **Probability of Brown Offspring:**
- Total offspring: 4 (2 BB + 2 Bb)
- Total brown offspring: 4
- Probability of brown rabbits = (Number of brown offspring / Total offspring) = 4/4 = 100%

So the answer is **D: 100%**.