Heterozygous tall plants were crossed with dwarf plants. What will be the ratio of dwarf plants in the progeny

Options

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

Answer

To solve the problem of determining the ratio of dwarf plants in the progeny when heterozygous tall plants are crossed with dwarf plants, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Genotypes of the Parents**:
- The heterozygous tall plant has the genotype **Tt** (where T is the dominant allele for tallness and t is the recessive allele for dwarfness).
- The dwarf plant is homozygous recessive with the genotype **tt**.

2. **Determine the Gametes Produced by Each Parent**:
- The heterozygous tall plant (Tt) can produce two types of gametes: **T** and **t**.
- The dwarf plant (tt) can only produce one type of gamete: **t**.

3. **Set Up a Punnett Square**:
- Create a Punnett square to visualize the possible combinations of gametes from the parents.
- The rows will represent the gametes from the heterozygous tall plant (T and t), and the columns will represent the gametes from the dwarf plant (t).

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

4. **Analyze the Offspring Genotypes**:
- From the Punnett square, we can see the resulting genotypes of the offspring:
- 2 offspring with genotype **Tt** (heterozygous tall)
- 2 offspring with genotype **tt** (homozygous dwarf)

5. **Calculate the Ratio of Dwarf Plants**:
- Out of a total of 4 offspring, 2 are dwarf (tt).
- Therefore, the ratio of dwarf plants in the progeny is **2 out of 4**, which simplifies to **1 out of 2** or **50%**.

### Final Answer:
The ratio of dwarf plants in the progeny is **50%**.

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