In the context of blood composition, which component is the fluid portion of blood?

• A. Leukocytes
• B. Platelets
• C. Erythrocytes
• D. Plasma

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the components of blood. Blood is composed of formed elements (cells and cell fragments) and a fluid portion.
2. Step 2: Identify the formed elements: Leukocytes (white blood cells), Platelets (cell fragments involved in clotting), and Erythrocytes (red blood cells). These are all cellular components.
3. Step 3: Recognize that the fluid portion of blood, which carries these formed elements, nutrients, hormones, and waste products, is called plasma.
4. Step 4: Recall that plasma is a straw-colored liquid that makes up about 55% of total blood volume and serves as the medium for transporting substances throughout the body.
5. Step 5: Conclude that among the options given, plasma is the fluid portion of blood, while leukocytes, platelets, and erythrocytes are cellular components suspended within it.