Question

what is one type of immune cell that relies on active transport? red blood cells macrophages stem cells

Explanation:

To solve this, we analyze each option:

• Red blood cells: Primarily carry oxygen, not immune cells relying on active transport for immune functions.
• Macrophages: Are immune cells. They use active transport (e.g., phagocytosis, a type of active transport for engulfing pathogens) as part of their immune response.
• Stem cells: Involved in cell renewal, not primarily immune cells with a focus on active transport for immune tasks.

Answer:

B. macrophages