In Mirabilis jalapa red and white coloured flowers are seen. When they are crossed all flowers are pink coloured in

Options

A. `F_1` generation
B. `F_2` generation
C. Both (a) and (b)
D. Gametes

Answer

To solve the question regarding the inheritance of flower color in Mirabilis jalapa, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Parent Flower Colors**:
- In Mirabilis jalapa, we have two parent flower colors: red and white.

2. **Understand the Cross**:
- When a red flower (let’s denote it as R) is crossed with a white flower (denote it as W), the resulting flowers in the first generation (F1) are all pink (denote it as P).

3. **Determine the Inheritance Pattern**:
- The pink color indicates that this is an example of incomplete dominance. In this case, neither red nor white is completely dominant over the other, leading to a blending of traits in the offspring.

4. **Genetic Representation**:
- We can represent the alleles as follows:
- R = Red allele
- W = White allele
- P = Pink phenotype (which is a mix of R and W)

5. **F1 Generation Result**:
- When we cross R (red) with W (white), all offspring (F1 generation) will be P (pink). Therefore, the genotype of all F1 plants can be represented as RW.

6. **Next Generation (F2 Generation)**:
- If we now self-cross the F1 generation (P x P), we can use a Punnett square to determine the F2 generation.
- The possible gametes from each parent (RW x RW) would be:
- R, W from the first parent
- R, W from the second parent

7. **Punnett Square Analysis**:
- The Punnett square would look like this:
```
R W
------------
R | RR | RW |
------------
W | RW | WW |
------------
```
- The genotypes from the square are:
- 1 RR (Red)
- 2 RW (Pink)
- 1 WW (White)

8. **Phenotypic Ratio**:
- From the Punnett square, we can see the phenotypic ratio of the F2 generation is:
- 1 Red : 2 Pink : 1 White

### Final Answer:
- The F1 generation consists of all pink flowers, and the F2 generation exhibits a phenotypic ratio of 1 Red : 2 Pink : 1 White.