When heterozygous red flowered plant is crossed with white flowered plant the progeny will show a ratio of
(a) 350 red : 350 white
(b) 450 red : 250 white
(c) 380 red: 220 white
(d) None of the above

Options

A. 350 red : 350 white
B. 450 red : 250 white
C. 380 red: 220 white
D. None of the above

Answer

To solve the problem of determining the progeny ratio when a heterozygous red flowered plant is crossed with a white flowered plant, we can follow these steps:

### Step 1: Identify the Genotypes
- The heterozygous red flowered plant has the genotype **Rr** (where R = red and r = white).
- The white flowered plant is homozygous and has the genotype **rr**.

### Step 2: Set Up the Cross
- We will cross the two plants: **Rr (red)** x **rr (white)**.

### Step 3: Determine the Gametes
- The gametes produced by the heterozygous red flowered plant (Rr) are **R** and **r**.
- The gametes produced by the white flowered plant (rr) are both **r**.

### Step 4: Create a Punnett Square
- Set up a Punnett square to visualize the cross:

```
r r
__________
| | |
R | Rr | Rr |
|____|____|
r | rr | rr |
|____|____|
```

### Step 5: Analyze the Offspring
- From the Punnett square, we see the potential offspring:
- **Rr** (red flowered) - 2 occurrences
- **rr** (white flowered) - 2 occurrences

### Step 6: Determine the Ratio
- The ratio of red to white flowers is:
- Red (Rr): 2
- White (rr): 2
- This simplifies to a ratio of **1:1**.

### Step 7: Apply the Ratio to Given Options
- Since the ratio is 1:1, we can apply this to the numbers given in the options:
- (a) 350 red : 350 white (1:1)
- (b) 450 red : 250 white (not 1:1)
- (c) 380 red : 220 white (not 1:1)
- (d) None of the above

### Conclusion
- The correct answer is **(a) 350 red : 350 white**, as it maintains the 1:1 ratio.

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