Which of the following is a cell fragment ?

Options

A. Blood platelets
B. Bone cells
C. Lymphocytes
D. Leucocytes

Answer

To determine which of the following is a cell fragment, we need to analyze the options provided:

1. **Blood Platelet (Thrombocyte)**: Blood platelets are indeed cell fragments. They are produced from the fragmentation of larger precursor cells in the bone marrow called megakaryocytes. Platelets play a crucial role in blood clotting.

2. **Bone Cell**: Bone cells, such as osteocytes, osteoblasts, and osteoclasts, are complete cells and not fragments. They are involved in the formation and maintenance of bone tissue.

3. **Lymphocyte**: Lymphocytes are a type of white blood cell (WBC) that plays a significant role in the immune response. They are whole cells, not fragments.

4. **Leukocyte**: Similar to lymphocytes, leukocytes are also whole white blood cells involved in the immune response and are not cell fragments.

Based on this analysis, the correct answer to the question "Which of the following is a cell fragment?" is **Blood Platelet (Thrombocyte)**.

### Step-by-Step Solution:
1. **Identify the options**: The options provided are blood platelet, bone cell, lymphocyte, and leukocyte.

2. **Define cell fragments**: Understand that cell fragments are pieces of cells that have broken off from larger cells.

3. **Analyze each option**:
- Blood Platelet: Recognize that these are fragments derived from megakaryocytes.
- Bone Cell: Identify that these are complete cells involved in bone structure.
- Lymphocyte: Acknowledge that these are whole immune cells.
- Leukocyte: Recognize that these are also whole immune cells.

4. **Select the correct answer**: Conclude that the only cell fragment among the options is the **Blood Platelet (Thrombocyte)**.