Due to the cross between `"TTRr" xx "ttrr"` the resultant progenies show what percent of tall, red flowered plants ?

Options

A. `50%`
B. `75%`
C. `25%`
D. `100%`

Answer

To solve the problem of determining the percentage of tall, red-flowered plants resulting from the cross between "TTRR" and "ttrr," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Genotypes**:
- The first parent plant has the genotype "TTRR," which means it is homozygous for both traits: tall (T) and red flowers (R).
- The second parent plant has the genotype "ttrr," which means it is homozygous recessive for both traits: short (t) and white flowers (r).

2. **Determine the Gametes**:
- The gametes produced by the first parent (TTRR) will be "TR" (since both alleles are dominant).
- The gametes produced by the second parent (ttrr) will be "tr" (since both alleles are recessive).

3. **Perform the Cross**:
- Using a Punnett square, we can cross the gametes from both parents:
```
| TR |
|--------|
| tr | TtRr (Tall, Red)
```
- The only possible combination from this cross is TtRr.

4. **Analyze the Progeny**:
- The offspring genotype TtRr indicates that they will be tall (T is dominant over t) and red-flowered (R is dominant over r).
- Since there are no other combinations possible from this cross, all progeny will be TtRr.

5. **Calculate the Percentage**:
- Since all progeny (100%) from this cross will be tall and red-flowered, the percentage of tall, red-flowered plants is 100%.

### Final Answer:
The resultant progenies show **100%** of tall, red-flowered plants.