Identify the plant tissue in which lignin is absent

Options

A. Collenchyma
B. Sclerenchyma fibers
C. Sclereids
D. Xylem tracheids

Answer

To identify the plant tissue in which lignin is absent, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Lignin**:
- Lignin is a complex organic polymer found in the cell walls of many plants, particularly in wood and bark. It provides rigidity and strength to the plant structure.

2. **Examine the Options**:
- We need to analyze the different types of plant tissues to determine which one does not contain lignin.

3. **Analyze Xylem Tracheids**:
- Xylem tracheids are part of the xylem tissue responsible for water transport. Their cell walls are thickened with lignin, so this option cannot be correct.

4. **Analyze Sclereids**:
- Sclereids are a type of sclerenchyma cell with thick, lignified walls that provide protection. Since they contain lignin, this option is also incorrect.

5. **Analyze Sclerenchyma Fibers**:
- Sclerenchyma fibers are dense cells with thick walls that are also lignified. They provide structural support, so this option is not correct either.

6. **Analyze Collenchyma**:
- Collenchyma cells have irregularly thickened cell walls primarily made of cellulose. They provide support and flexibility to the plant but do not contain lignin in their primary walls.

7. **Conclusion**:
- Based on the analysis, the plant tissue in which lignin is absent is **collenchyma**.

### Final Answer:
The plant tissue in which lignin is absent is **collenchyma**.

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