In which of the following types a ridge is formed along the ventral suture of the ovary ?

Options

A. Marginal placentation
B. Free central placentation
C. Basal placentation
D. Axile placentation

Answer

To solve the question regarding the type of placentation where a ridge is formed along the ventral suture of the ovary, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Placentation**:
- Placentation refers to the arrangement of ovules within the ovary of a flower. It is crucial to know the different types of placentation to answer the question.

2. **Identifying the Types of Placentation**:
- There are several types of placentation, including:
- Marginal placentation
- Free central placentation
- Basal placentation
- Axial placentation
- Parietal placentation

3. **Analyzing Each Type**:
- **Marginal Placentation**: In this type, the placenta forms a ridge along the ventral suture of the ovary, and ovules are attached to this ridge. An example is the pea plant.
- **Free Central Placentation**: Here, the ovules are attached to a central axis, and there are no septa present.
- **Basal Placentation**: The placenta develops at the base of the ovary, with ovules attached at the bottom.
- **Axial Placentation**: In this type, the placenta is located along the central axis of a multilocular ovary, as seen in plants like the china rose.
- **Parietal Placentation**: The placenta forms along the inner walls of the ovary.

4. **Determining the Correct Answer**:
- Since the question specifically asks for the type where a ridge is formed along the ventral suture of the ovary, the correct answer is **Marginal Placentation**.

### Final Answer:
The type of placentation where a ridge is formed along the ventral suture of the ovary is **Marginal Placentation**.