When Mendel self pollinated the `F_(1)` plants of genotype RrYy, in the `F_(2)` generation, the yellow and green colour segregated in the ratio

Options

A. `1:2:1`
B. `3:1`
C. `9:3:3:1`
D. `1:1`

Answer

To solve the question regarding the segregation ratio of yellow and green colors in the F2 generation when Mendel self-pollinated the F1 plants of genotype RrYy, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Genotype**: The F1 plants have the genotype RrYy, where:
- R (Round seed) is dominant over r (Wrinkled seed).
- Y (Yellow seed) is dominant over y (Green seed).

2. **Identify the Traits**: The traits being studied are:
- Seed shape: Round (R) vs. Wrinkled (r)
- Seed color: Yellow (Y) vs. Green (y)

3. **Determine Gametes**: When the F1 plants (RrYy) are self-pollinated, they can produce the following gametes:
- RY (Round Yellow)
- Ry (Round Green)
- rY (Wrinkled Yellow)
- ry (Wrinkled Green)

4. **Set Up the Punnett Square**: Create a 4x4 Punnett square to determine the genotypes of the F2 generation from the gametes:
```
RY Ry rY ry
-----------------------------
RY | RRY Y | RRY y | RrY Y | RrY y |
-----------------------------
Ry | RRY y | Rry y | RrY y | Rry y |
-----------------------------
rY | RrY Y | RrY y | rrY Y | rrY y |
-----------------------------
ry | RrY y | RrY y | rrY y | rry y |
```

5. **Count the Phenotypes**: From the Punnett square, we can count the phenotypes:
- Round Yellow (R_Y): 9 (RRY Y + RRY y + RrY Y + RrY y)
- Round Green (R_y): 3 (Rry y)
- Wrinkled Yellow (rY): 3 (RrY y)
- Wrinkled Green (ry): 1 (rrY y)

6. **Calculate Yellow and Green Ratios**:
- Total Yellow (R_Y): 9 (Round Yellow) + 3 (Wrinkled Yellow) = 12
- Total Green (R_y): 3 (Round Green) + 1 (Wrinkled Green) = 4

7. **Determine the Ratio**: The ratio of yellow to green in the F2 generation is:
- Yellow: 12
- Green: 4
- Therefore, the ratio of yellow to green is 12:4, which simplifies to 3:1.

### Final Answer:
The yellow and green color segregated in the ratio of **3:1**.

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