Which of the following is not a feature of parietal placentation?

Options

A. The ovules develop on the inner wall of the ovary or on peripheral part.
B. Ovary is one-chambered but it becomes two chambered
C. Placenta develops at the base of ovary and a single ovule is attached to it
D. Present in Mustard and Argemone.

Answer

To determine which of the following is not a feature of parietal placentation, we need to analyze the characteristics of parietal placentation. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand Parietal Placentation
Parietal placentation is a type of placentation where the ovules develop on the inner wall of the ovary.

**Hint:** Remember that the location of ovule development is key to identifying placentation types.

### Step 2: Characteristics of Parietal Placentation
1. **Ovary Structure**: The ovary is typically one-chambered but can appear two-chambered due to the presence of a false septum known as the replum.

**Hint:** Focus on how the ovary's structure can change due to the presence of a false septum.

2. **Ovule Arrangement**: In parietal placentation, multiple ovules are attached to the inner wall of the ovary, not just a single ovule.

**Hint:** Count the number of ovules and their arrangement; this is crucial for identifying the type of placentation.

3. **Examples**: Common examples of plants exhibiting parietal placentation include mustard and agrimony.

**Hint:** Knowing examples can help solidify your understanding of the concept.

### Step 3: Analyze the Options
Now, let’s evaluate the options provided in the question:
1. **Ovules develop on the inner wall of the ovary** - This is a feature of parietal placentation.
2. **Ovary is one-chambered but becomes two-chambered due to false septum** - This is also a feature of parietal placentation.
3. **Placenta develops in ovary base and a single ovule is attached** - This is NOT a feature of parietal placentation, as multiple ovules are attached, not just one.
4. **Placenta is present in Mustard and Agrimon** - This is a correct statement regarding parietal placentation.

### Step 4: Conclusion
Based on the analysis, the option that is NOT a feature of parietal placentation is option 3: "Placenta develops in ovary base and a single ovule is attached."

**Final Answer:** Option 3 is the correct answer.