Which pair has lignin in both?
(a) Tracheids and collenchyma
(b) Schlerenchyma and sieve tube
(c) Schlerenchyma and traheids
(d) Parenchyma and endodermis

Options

A. Tracheids and collenchyma
B. Schlerenchyma and sieve tube
C. Schlerenchyma and traheids
D. Parenchyma and endodermis

Answer

To determine which pair has lignin in both types of cells, we need to analyze each option carefully:

1. **Understanding Lignin**: Lignin is a complex organic polymer found in the cell walls of many plants. It provides rigidity and strength, making the cells more resistant to decay and mechanical stress. Cells that contain lignin are typically dead at maturity.

2. **Analyzing Each Option**:
- **(a) Tracheids and Collenchyma**:
- Tracheids are elongated cells in the xylem that are lignified and help in water conduction and support.
- Collenchyma, on the other hand, provides flexible support and does not contain lignin in significant amounts. Therefore, this pair does not have lignin in both.

- **(b) Sclerenchyma and Sieve Tube**:
- Sclerenchyma cells are known for their thick lignified walls and provide structural support.
- Sieve tubes, part of the phloem, are living cells that do not have lignin in their walls. Thus, this pair does not have lignin in both.

- **(c) Sclerenchyma and Tracheids**:
- Sclerenchyma cells are indeed lignified and provide support.
- Tracheids are also lignified cells that serve in water conduction and support.
- Therefore, both sclerenchyma and tracheids contain lignin, making this pair correct.

- **(d) Parenchyma and Endodermis**:
- Parenchyma cells are generally living cells with thin walls and do not contain lignin.
- The endodermis may have some lignin but is primarily composed of living cells. Thus, this pair does not have lignin in both.

3. **Conclusion**: The correct answer is (c) Sclerenchyma and Tracheids, as both types of cells contain lignin.

### Final Answer:
(c) Sclerenchyma and Tracheids