If selfing occurs in the plant having genotype RrYy, then ratio of given genotype will be :- RRYY, RRYy, RrYy

Options

A. `1:2:2:4`
B. `1:2:2:1`
C. `1:1:1:1`
D. `2:2:2:1`

Answer

To solve the problem of determining the genotype ratio from selfing a plant with the genotype RrYy, we can follow these steps:

### Step 1: Identify the Genotype
The given genotype is RrYy, which is heterozygous for both traits (R and Y). Here, R represents a dominant trait and r represents a recessive trait. Similarly, Y is a dominant trait and y is a recessive trait.

### Step 2: Determine Gamete Formation
When selfing occurs (crossing the plant with itself), we need to determine the possible gametes that can be produced by the genotype RrYy. The gametes can be formed by combining one allele from each gene:

- From Rr, the possible alleles are R and r.
- From Yy, the possible alleles are Y and y.

Thus, the possible gametes from RrYy are:
- RY
- Ry
- rY
- ry

### Step 3: Create a Punnett Square
Next, we can create a Punnett square to visualize the offspring ratios. We will put the gametes from one parent on the top and the gametes from the other parent on the side:

```
RY Ry rY ry
-------------------------
RY | RRYY | RRYy | RrYY | RrYy |
-------------------------
Ry | RRYy | RRyy | RrYy | Rryy |
-------------------------
rY | RrYY | RrYy | rrYY | rrYy |
-------------------------
ry | RrYy | Rryy | rrYy | rryy |
-------------------------
```

### Step 4: Count the Genotypes
Now, we can count the occurrences of each genotype in the Punnett square:

1. **RRYY**: 1
2. **RRYy**: 2
3. **RrYY**: 2
4. **RrYy**: 4
5. **RRyy**: 1
6. **Rryy**: 2
7. **rrYY**: 1
8. **rrYy**: 2
9. **rryy**: 1

### Step 5: Calculate the Ratio
Now we can summarize the counts of the specific genotypes we are interested in:

- **RRYY**: 1
- **RRYy**: 2
- **RrYy**: 4

Thus, the ratio of the genotypes RRYY, RRYy, and RrYy is:
- RRYY : RRYy : RrYy = 1 : 2 : 4

### Final Answer
The ratio of the given genotypes (RRYY, RRYy, RrYy) when selfing occurs in the plant with genotype RrYy is **1:2:4**.

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