What do the antibodies secreted by plasma cells (the effector cells of humoral immunity) do to attack their targets?

• A. Activate complement to form a pore in the membrane of the targets
• B. Clump cells together so that phagocytes can ingest them
• C. Cross-link soluble antigen molecules, forming immobile aggregates
• D. Attach to antigens and block their activity
• E. All of the listed responses are correct.

Answer: (E)

Verified step by step guidance

1. Understand that antibodies are proteins produced by plasma cells, which are a type of white blood cell involved in the immune response.
2. Recognize that antibodies can neutralize pathogens by binding to antigens, which are specific molecules on the surface of pathogens, and blocking their activity.
3. Learn that antibodies can activate the complement system, a group of proteins that assist in destroying pathogens by forming pores in their membranes, leading to cell lysis.
4. Know that antibodies can cause agglutination, which is the clumping of cells, making it easier for phagocytes to ingest and destroy them.
5. Realize that antibodies can cross-link soluble antigens, forming large, immobile aggregates that can be more easily cleared by the immune system.