The elongated or tube-like cells, with thick , lignified walls and tapering ends are

Options

A. Tracheids
B. Vessels
C. Xylem fiber
D. Xylem parenchyma

Answer

To solve the question regarding the elongated or tube-like cells with thick, lignified walls and tapering ends, we can analyze the options provided:

1. **Tracheids**: These are elongated, tube-like cells found in the xylem of vascular plants. They have thick, lignified walls and tapering ends. Tracheids are primarily responsible for the conduction of water and minerals and provide structural support. They do not have perforations, which distinguishes them from vessels.

2. **Vessels**: These are also tubular structures found in the xylem, but they are generally wider than tracheids and have perforations at their ends, allowing for more efficient water transport.

3. **Xylem fibers**: These are supportive cells that are also elongated but are primarily meant for structural support rather than conduction. They have thick walls but are not specifically defined by their tapering ends.

4. **Xylem parenchyma**: These are living cells with thin cell walls made of cellulose, primarily involved in storage and not characterized by thick lignified walls or tapering ends.

Based on the analysis, the correct answer to the question is **tracheids**.

### Step-by-Step Solution:
1. **Identify the characteristics of the cells described in the question**: Elongated or tube-like, thick lignified walls, and tapering ends.
2. **Examine each option**:
- **Tracheids**: Match the description perfectly.
- **Vessels**: Have perforations, not matching the description.
- **Xylem fibers**: While elongated, they are not primarily defined by the features mentioned.
- **Xylem parenchyma**: Do not match the description due to thin walls.
3. **Conclude that the correct answer is tracheids** because they fulfill all the criteria mentioned in the question.