Which of the following is present in both plasma and serum in humans.

Options

A. WBCs
B. Fibrinogen
C. RBCs
D. Albumin

Answer

To answer the question "Which of the following is present in both plasma and serum in humans?", we will analyze the options provided and determine which component is found in both blood plasma and serum.

### Step-by-Step Solution:

1. **Understanding Plasma and Serum**:
- Plasma is the liquid component of blood that contains water, electrolytes, proteins (including clotting factors), hormones, and waste products.
- Serum is the fluid that remains after blood has clotted. It is essentially plasma without the clotting factors.

2. **Analyzing the Options**:
- **Option 1: WBC (White Blood Cells)**:
- WBCs are present in plasma but are not present in serum because they are part of the formed elements that are removed during clotting.
- **Option 2: Fibrinogen**:
- Fibrinogen is a clotting factor that is present in plasma but is absent in serum, as it is consumed during the clotting process.
- **Option 3: RBC (Red Blood Cells)**:
- RBCs are also present in plasma but are not found in serum for the same reason as WBCs; they are removed during the clotting process.
- **Option 4: Albumin**:
- Albumin is a protein that is present in both plasma and serum. It is not involved in clotting and thus remains in serum after clotting occurs.

3. **Conclusion**:
- The only component that is present in both plasma and serum is **albumin**. Therefore, the correct answer is **Option 4: Albumin**.

### Final Answer:
**Albumin is present in both plasma and serum in humans.**

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