In Andulassian fowl, the heterozygous condition of alleles for black plumage (B) and white (b) is blue. A blue andulasian fowl is bred to a black andulasian fowl, the proportion of the offspring will be

Options

A. 50% white: 50% blue
B. 50% black: 50% blue
C. 50% black: 50% white
D. 25% black: 25% blue: 50% white

Explanation

To solve the problem, we need to understand the genetics of the Andalusian fowl and how to use a Punnett square to determine the offspring ratios from a cross between two fowls.

### Step-by-Step Solution:

1. **Identify the Genotypes**:
- The black plumage is represented by the allele B (homozygous BB) and the white plumage by the allele b (homozygous bb).
- The heterozygous condition (Bb) results in blue plumage.

2. **Determine the Cross**:
- We are crossing a blue Andalusian fowl (Bb) with a black Andalusian fowl (BB).

3. **Gametes Formation**:
- The blue fowl (Bb) can produce two types of gametes: B and b.
- The black fowl (BB) can only produce one type of gamete: B.

4. **Set Up the Punnett Square**:
- Create a 2x1 Punnett square to visualize the cross:
```
B | B
---------------
B | BB | BB
b | Bb | Bb
```

5. **Analyze the Offspring Genotypes**:
- From the Punnett square, we see the following genotypes:
- 2 BB (black)
- 2 Bb (blue)

6. **Calculate the Proportions**:
- The total number of offspring is 4 (2 BB + 2 Bb).
- The proportion of black (BB) to blue (Bb) is 2:2, which simplifies to 1:1.

7. **Conclusion**:
- Therefore, the proportion of the offspring will be 1 black (BB) to 1 blue (Bb), or 50% black and 50% blue.

### Final Answer:
The proportion of the offspring will be 1:1 (50% black and 50% blue).

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