Which one of the following types of cells lack nucleus in humans ?

Options

A. RBC
B. Neutrophils
C. Eosinosphils
D. Monocyte

Answer

To solve the question "Which one of the following types of cells lack nucleus in humans?", we can follow these steps:

### Step 1: Identify the types of cells mentioned in the options
The options provided are:
- A) RBC (Red Blood Cells)
- B) Neutrophils
- C) Eosinophils
- D) Monocytes

### Step 2: Understand the characteristics of each cell type
- **RBC (Red Blood Cells)**: These cells are responsible for transporting oxygen from the lungs to the rest of the body. In humans, mature RBCs lack a nucleus.
- **Neutrophils**: These are a type of white blood cell (WBC) that have a nucleus and play a crucial role in the immune response.
- **Eosinophils**: Another type of WBC that also contains a nucleus and is involved in combating multicellular parasites and certain infections.
- **Monocytes**: These are large WBCs that have a nucleus and are part of the immune system, differentiating into macrophages and dendritic cells.

### Step 3: Analyze the information
From the above characteristics, we see that:
- Only RBCs are known to lack a nucleus in their mature form.
- All other options (neutrophils, eosinophils, and monocytes) contain a nucleus.

### Step 4: Conclusion
Based on the analysis, the correct answer to the question is:
**A) RBC (Red Blood Cells)**