Common Solutes in Circulatory and Interstitial Fluids

Steps:

• Blood in vessels contains dissolved CO2, glucose, white blood cells (WBCs), and antibodies in plasma.
• Lymph, derived from tissue fluid, includes CO2, glucose, antibodies, and WBCs like lymphocytes.
• Tissue fluid (interstitial fluid) has CO2 and glucose as solutes, plus low levels of antibodies from plasma leakage, but lacks significant WBCs, which are mainly in blood and lymph.
• Thus, only CO2, glucose, and antibodies are universally present across all three.

Why A is correct:

• CO2, glucose, and antibodies are plasma-derived solutes that diffuse into lymph and tissue fluid, ensuring their presence in all.

Why the others are wrong:

• B includes WBCs, which are absent or minimal in tissue fluid.
• C includes WBCs but excludes antibodies, which are immunoglobulins in plasma accessible to all fluids.
• D excludes CO2, a key waste gas transported dissolved in all fluids.

Final answer: A