__________ is absent in most of the monocotyledons, stem:

Options

A. Sieve tube elements
B. Phloem parenchyma
C. Xylem parenchyma
D. Companion cells

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which component is absent in most monocotyledon stems. The options provided are sieve tube elements, phloem parenchyma, xylem parenchyma, and companion cells.

2. **Identifying the Components**:
- **Sieve Tube Elements**: These are part of the phloem and are responsible for the transport of nutrients.
- **Phloem Parenchyma**: These are parenchyma cells located between the sieve tubes in the phloem and primarily function in food storage.
- **Xylem Parenchyma**: These cells are part of the xylem and help in the storage of nutrients and water.
- **Companion Cells**: These are specialized parenchyma cells that assist sieve tube elements in the phloem.

3. **Analyzing Monocotyledons**: In monocot stems, the structure of the vascular tissue is different from that in dicots. While monocots have sieve tube elements, xylem parenchyma, and companion cells, they typically lack phloem parenchyma.

4. **Conclusion**: Based on the analysis, the correct answer to the question is **phloem parenchyma**, as it is absent in most monocotyledon stems.

**Final Answer**: Phloem parenchyma is absent in most of the monocotyledon stems.

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