Torus is concerned with

Options

A. boardered pits
B. thalamus
C. both (1) and (2)
D. vessels

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Torus:**
- The term "torus" refers to a specific structure found in the bordered pits of plant cells. It is a thickened area that plays a crucial role in the function of these pits.

2. **Identifying the Location of Torus:**
- The torus is located within the bordered pits, which are openings in the cell wall that allow for the movement of water and nutrients between adjacent plant cells.

3. **Structure of Bordered Pits:**
- Bordered pits consist of a thin area of the primary wall, which is surrounded by a thicker secondary wall. The torus is a central thickening in the pit that can regulate the flow of substances through the pit.

4. **Composition of Torus:**
- The torus is primarily composed of lignin, a complex organic polymer that provides structural support to the plant. In some cases, it may also contain suberin.

5. **Function of Torus:**
- The torus helps to control the functional activities of the pit by acting as a valve. It can close off the pit in response to changes in pressure or moisture, thus regulating the flow of water and solutes.

6. **Conclusion:**
- Therefore, the torus is specifically concerned with the bordered pits in plant cells, making it an important structure for plant physiology.

**Final Answer:**
The torus is concerned with bordered pits in plant cells.

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