Andalusian fowls have two pure forms - black and white. If black forms (BB) and white forms (WW) are crossed `F_(1)` individuals appear blue coloured (BW), due to incomplete dominance. Which of the following would be an outcome of a cross between black form and blue form ?

Options

A. 1 Blank : 2 Blue : 1 White
B. 2 Black : 1 Blue
C. 1 Black : 2 Blue
D. 1 Black : 1 Blue

Explanation

To solve the problem of the cross between black Andalusian fowls (BB) and blue fowls (BW), we can follow these steps:

### Step 1: Identify the Genotypes
- The black fowl has the genotype BB (homozygous).
- The blue fowl has the genotype BW (heterozygous).

### Step 2: Determine the Gametes
- The black fowl (BB) can only produce one type of gamete: B.
- The blue fowl (BW) can produce two types of gametes: B and W.

### Step 3: Set Up a Punnett Square
- Create a Punnett square to visualize the possible offspring from the cross.

```
B B
----------------
B | BB BB
----------------
W | BW BW
```

### Step 4: Analyze the Offspring Genotypes
- From the Punnett square, we can see the possible genotypes of the offspring:
- 2 BB (black)
- 2 BW (blue)

### Step 5: Determine the Phenotypic Ratio
- The phenotypic ratio can be calculated from the genotypes:
- 2 black (BB) : 2 blue (BW) simplifies to a ratio of 1:1.

### Conclusion
- The outcome of the cross between the black form (BB) and the blue form (BW) is a 1:1 ratio of black to blue fowls.

### Final Answer
- The outcome of the cross is 1 black fowl (BB) and 1 blue fowl (BW).

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