Thick irregular but permeable walls occur in

Options

A. sulereides
B. fibres
C. transfer cells
D. tracheides

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the occurrence of "thick irregular but permeable walls" in plant anatomy. To answer this, we need to identify which type of plant cell or tissue exhibits these characteristics.

2. **Defining Permeable**: The term "permeable" refers to the ability of a material to allow substances (solids, liquids, gases) to pass through it. In the context of plant cells, this means that the walls of certain cells can facilitate the movement of nutrients and other materials.

3. **Identifying Relevant Cell Types**: In plant anatomy, there are various types of cells, including parenchyma, sclerenchyma, and vascular tissues. Among these, we need to find which type has thick, irregular, and permeable walls.

4. **Considering Transfer Cells**: Transfer cells are specialized cells that play a significant role in the transportation of nutrients within plants. They are characterized by having thick walls that are also irregular in shape.

5. **Role of Cell Membrane Enfoldings**: Transfer cells have unique features such as enfoldings of the cell membrane. These enfoldings increase the surface area of the cell, which enhances the cell's ability to transfer nutrients, particularly sugars, from one part of the plant (source) to another (sink).

6. **Conclusion**: Based on the characteristics discussed, the type of cell that has thick irregular but permeable walls is the **transfer cells**. These cells are essential for nutrient transport in plants.

**Final Answer**: Thick irregular but permeable walls occur in **transfer cells**.

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