`F_(2)` ratio in chicken came out to be 9 rose comb blacks, 1 single comb white, 3 rose comb whites and 3 single comb blacks. Which are the recessive ?

Options

A. Single comb, white plumage
B. Rose comb, white plumage
C. Single comb, black plumage
D. Rose comb, black plumage.

Answer

To determine which traits are recessive in the given F2 generation of chickens, we can analyze the phenotypic ratios provided in the question. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Understanding the F2 Ratio**:
The F2 generation ratio is given as:
- 9 rose comb blacks
- 1 single comb white
- 3 rose comb whites
- 3 single comb blacks

2. **Identifying the Traits**:
We have two traits to consider:
- Comb type: Rose comb and single comb
- Color: Black and white

3. **Counting the Combinations**:
- Rose comb (black + white): 9 (black) + 3 (white) = 12
- Single comb (black + white): 3 (black) + 1 (white) = 4

4. **Determining Dominance**:
- Since rose comb appears more frequently (12 times) compared to single comb (4 times), we can infer that rose comb is the dominant trait.
- Among the colors, black appears more frequently (9 + 3 = 12) compared to white (1 + 3 = 4), suggesting that black is the dominant color.

5. **Identifying the Recessive Traits**:
- The single comb trait appears less frequently (4 times) compared to the rose comb (12 times), indicating that single comb is recessive.
- The white color also appears less frequently (4 times) compared to black (12 times), indicating that white is recessive.

6. **Conclusion**:
The recessive traits in this F2 generation are:
- Single comb (as it appears only 4 times)
- White color (as it appears only 4 times)

### Final Answer:
The recessive trait is **single comb white plumage**.

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