In the context of specialized connective tissue (blood), what type of mixture is blood?

• A. A homogeneous mixture (a true solution)
• B. A pure substance (single compound)
• C. A colloid with no suspended particles
• D. A heterogeneous mixture (a suspension of formed elements in plasma)

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the components of blood. Blood consists of plasma (the liquid part) and formed elements (such as red blood cells, white blood cells, and platelets).
2. Step 2: Define the types of mixtures: a homogeneous mixture (true solution) has uniform composition throughout; a pure substance is a single compound; a colloid contains small particles dispersed but not settled; a heterogeneous mixture has visibly different components or phases.
3. Step 3: Analyze blood's composition: plasma is a solution containing dissolved substances, but the formed elements are suspended particles that can settle out, indicating non-uniformity.
4. Step 4: Recognize that because blood contains suspended formed elements in plasma, it is not a true solution or pure substance, nor is it a colloid without suspended particles.
5. Step 5: Conclude that blood is best classified as a heterogeneous mixture, specifically a suspension of formed elements in plasma.