If a homozygous tall plant is crossed with a dwarf plant, what shall be the ratio of plants in offsprings :-

Options

A. All heterozygous tall
B. Two tall & Two dwarf
C. `1:2:1`
D. All homozygous dwarf

Answer

To solve the question of the offspring ratio when a homozygous tall plant is crossed with a dwarf plant, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Genotypes**:
- A homozygous tall plant can be represented as **TT** (where T is the dominant allele for tallness).
- A dwarf plant, being homozygous recessive, can be represented as **tt** (where t is the recessive allele for dwarfism).

2. **Set Up the Cross**:
- We are crossing **TT** (homozygous tall) with **tt** (homozygous dwarf).

3. **Use a Punnett Square**:
- Draw a Punnett square to visualize the genetic cross.
- Place the alleles of one parent on the top and the alleles of the other parent on the side:
```
T T
---------
t | Tt | Tt |
---------
t | Tt | Tt |
---------
```

4. **Fill in the Punnett Square**:
- Each box represents a possible genotype of the offspring.
- In this case, all combinations will yield **Tt** (heterozygous tall).

5. **Determine the Offspring Ratio**:
- Since all offspring are **Tt**, they will all express the tall phenotype because the tall allele (T) is dominant over the dwarf allele (t).
- Therefore, the ratio of the offspring will be **100% tall plants**.

### Final Answer:
The ratio of plants in the offspring will be **all heterozygous tall (Tt)**.

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