Heterozygous tall plant is crossed with a homozygous dwarf plant then the percentage of progeny having dwarf character is

Options

A. 0
B. 0.25
C. 0.5
D. 1

Answer

To solve the problem of determining the percentage of progeny having the dwarf character when a heterozygous tall plant is crossed with a homozygous dwarf plant, we can follow these steps:

### Step 1: Define the Genotypes
- Let **T** represent the dominant allele for tallness.
- Let **t** represent the recessive allele for dwarfism.
- The heterozygous tall plant will have the genotype **Tt** (one dominant and one recessive allele).
- The homozygous dwarf plant will have the genotype **tt** (two recessive alleles).

### Step 2: Set Up the Cross
- We are crossing a **Tt** (heterozygous tall) plant with a **tt** (homozygous dwarf) plant.

### Step 3: Create a Punnett Square
- The Punnett square will help us visualize the possible genotypes of the offspring.

```
T t
----------------
t | Tt | tt |
----------------
t | Tt | tt |
----------------
```

### Step 4: Analyze the Results
- From the Punnett square, we can see the possible genotypes of the offspring:
- **Tt** (tall) - 2 occurrences
- **tt** (dwarf) - 2 occurrences

### Step 5: Calculate the Percentage of Dwarf Progeny
- There are a total of 4 offspring (2 Tt and 2 tt).
- The number of dwarf progeny (tt) is 2.
- To find the percentage of dwarf progeny, we use the formula:

\[ \text{Percentage of dwarf progeny} = \left(\frac{\text{Number of dwarf progeny}}{\text{Total number of progeny}}\right) \times 100 \]

\[ \text{Percentage of dwarf progeny} = \left(\frac{2}{4}\right) \times 100 = 50\% \]

### Conclusion
- The percentage of progeny having the dwarf character is **50%**.

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