IGCSE Biology 9 Views 1 Answers
Avatar for Sourav Pan
Sourav PanNovember 14, 2024

State the functions of: (a) lymphocytes – antibody production (b) phagocytes – engulfing pathogens by phagocytosis

State the functions of: (a) lymphocytes – antibody production (b) phagocytes – engulfing pathogens by phagocytosis

Sourav Pan
Sourav PanNovember 14, 2024

Answered step-by-step

Here are the functions of lymphocytes in antibody production and phagocytes in engulfing pathogens by phagocytosis:

(a) Lymphocytes – Antibody Production

  • Function: Lymphocytes, specifically B cells, are crucial for the adaptive immune response. Their primary role is to produce antibodies that target specific antigens (foreign substances such as bacteria and viruses).
  • Mechanism:
    • When a B cell encounters an antigen that matches its specific receptor, it binds to the antigen, which activates the B cell.
    • The activated B cell undergoes clonal expansion, multiplying into a large number of identical cells.
    • Some of these cells differentiate into plasma cells, which are specialized for producing large quantities of antibodies. These antibodies are released into the bloodstream and lymphatic system.
    • The antibodies bind to the specific antigens, marking them for destruction or neutralization by other immune cells. This process is essential for clearing infections and providing long-term immunity through memory B cells, which remain in the body to respond more rapidly if the same antigen is encountered again in the future.

(b) Phagocytes – Engulfing Pathogens by Phagocytosis

  • Function: Phagocytes, including neutrophils and macrophages, are key players in the innate immune response. Their primary role is to identify, engulf, and destroy pathogens and debris through a process called phagocytosis.
  • Mechanism:
    • When a phagocyte detects pathogens (often through pattern recognition receptors that bind to pathogen-associated molecular patterns), it initiates phagocytosis.
    • The phagocyte extends its plasma membrane around the pathogen, forming pseudopodia that surround and engulf the particle.
    • Once fully enclosed, the pathogen is trapped in a membrane-bound vesicle known as a phagosome.
    • The phagosome then fuses with lysosomes to form a phagolysosome, where digestive enzymes and reactive oxygen species break down and destroy the engulfed pathogen.
    • This process not only eliminates pathogens but also helps present antigens from the pathogens on the surface of phagocytes to activate other immune cells, thus linking innate and adaptive immunity

Start Asking Questions

This site uses Akismet to reduce spam. Learn how your comment data is processed.

⚠️
  1. Click on your ad blocker icon in your browser's toolbar
  2. Select "Pause" or "Disable" for this website
  3. Refresh the page if it doesn't automatically reload