In between the vascular bundles of dicot stem there are a few layers of radially placed parenchymatous cells, which constitute

Options

A. Pericycle
B. Medullary rays
C. Endodermis
D. Pith

Answer

To answer the question regarding the layers of radially placed parenchymatous cells found between the vascular bundles of a dicot stem, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure**: In a dicot stem, the vascular bundles are arranged in a ring. Between these vascular bundles, there are layers of cells that are radially arranged.

2. **Understand the Cell Type**: The cells that are found in these layers are parenchymatous cells. Parenchyma is a type of plant tissue that is typically involved in storage, photosynthesis, and tissue repair.

3. **Define the Function and Arrangement**: The parenchymatous cells between the vascular bundles serve as a connection between the xylem and phloem, facilitating the transport of nutrients and water. These layers run radially from the center of the stem to the outer layers.

4. **Name the Structure**: The specific name for these layers of parenchymatous cells is "medullary rays." Medullary rays are also referred to as "wood rays" and are important for the radial transport of substances within the stem.

5. **Eliminate Incorrect Options**:
- Pericycle is located beneath the cortex and is not the correct answer.
- Endodermis is also beneath the pericycle and does not fit the description.
- Pith is the central part of the stem and does not refer to the layers between vascular bundles.

6. **Conclusion**: Therefore, the correct answer to the question is **medullary rays**.

### Final Answer:
The layers of radially placed parenchymatous cells between the vascular bundles of a dicot stem constitute **medullary rays**.

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