A dwarf pea plant is treated with gibberellin which makes it tall. This plant is crossed with genetically pure tall plant. Phenotypic ratio in next generation shall be

Options

A. 3 tall : 1 dwarf
B. 50% tall: 50% dwarf
C. all tall
D. all dwarf

Explanation

To solve the problem step by step, we need to analyze the genetics of the dwarf pea plant and the tall pea plant, taking into consideration the effects of gibberellin.

### Step-by-Step Solution:

1. **Understanding the Genotypes**:
- The dwarf pea plant has a genotype of **tt** (homozygous recessive).
- The tall pea plant is genetically pure, meaning its genotype is **TT** (homozygous dominant).

2. **Effect of Gibberellin**:
- Gibberellin treatment makes the dwarf plant appear tall, but it does not change its genetic makeup. Therefore, the genotype of the treated dwarf plant remains **tt**.

3. **Crossing the Plants**:
- We cross the treated dwarf plant (**tt**) with the tall plant (**TT**).
- The gametes produced by the tall plant will be **T** (since it can only produce T).
- The gametes produced by the dwarf plant will be **t** (since it can only produce t).

4. **Punnett Square**:
- We can set up a Punnett square to visualize the cross:
```
T | T
---------------
t | Tt | Tt
---------------
t | Tt | Tt
```
- From the Punnett square, we see that all offspring will have the genotype **Tt**.

5. **Phenotypic Ratio**:
- Since **T** is dominant over **t**, all offspring (Tt) will exhibit the tall phenotype.
- Therefore, the phenotypic ratio of the next generation will be **100% tall**.

### Final Answer:
The phenotypic ratio in the next generation shall be **all tall plants** (or 100% tall).

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