immune system biology alevel

• B cells develop from stem cells in the bone marrow and mature into either naïve B cells or memory B cells.
• Name the two different types of phagocytes.


  neutrophils and macrophages
• What does the phagosome fuse with during the digestion process?


  lysosome to form a phagolysosome
• What happens to the excreted remains following phagocytosis?


  dissolved into the bloodstream by exocytosis, used up by the phagocyte.
• name as many different types of primary defence mechanisms...


  skin, stomach acid, tear, mucus, cilia, ear wax, sweat.
• name the two types of secondary immune responses 


  phagocytosis and inflammation
• will a primary immune response make you sick?


  yes, a primary immune response is in response to the first exposure to a foreign/non-self antigen.
• will a secondary immune response make you sick? 


  no, a secondary immune response will not make you sick as it is second encounter of this foreign antigen meaning the immune system will respond quicker.
• why do we not get sick during a secondary immune response? 


  memory B and T cells already prepared with the antibody to rapidly respond to the foreign antigen, so we don't need to go through clonal selection.
• is the humoral response specific or non specific?


  specific immune response
• is the cell mediated response a specific or non specific response?


  specific immune response
• does the humoral response use B-lymphocytes or T-lymphocytes and what do they do? 


  B-lymphocytes, they are specifically selected to neutralise the pathogen.
• where do B-lymphocytes develop and mature?


  bone marrow
• how many proteins does one b-cell have on it membrane and when are these proteins used?


  B cells have a single protein called and antibody. These antibodies are secreted in response to a specific antigen.
• what is the b cell known as when its antibody matches with a specific antigen? 


  the b cell will become component to that specific antigen
• the antibodies act as a homing beacon for what type of cell?


  the antibodies signal more macrophages to come a destroy the pathogens.
• what is the role of the b cells?

  • B cells will receive the foreign antigen from the pathogen or the APC’s (Antigen-Presenting Cells) 
  • Similarly to the APC’s the B-cells will present this antigen on their cell surface. 
  • T helper cells will bind to this antigen and activate the rest of the B-cells.
  • The now activated B-cells will begin to divide by mitosis (clone themselves) 
  • They will begin to form plasma and memory cells, this is known as clonal selection
  • The plasma cells produce antibodies that are complementary to the antigens.
• how do antibodies move around the body?

  antibodies are soluble in blood and tissue fluid so it is easy for them to move around the body.
• what will happen when the antibody find the complementary antigen?

  the antibody will only bind to the antigen if it has the correct specific shape.
• what is it called when an antibody binds with the complementary antigen?

  when the antibody and antigen bind it is known as a antigen-antibody complex
• Where do T lymphocytes mature

  T lymphocytes mature in the thymus
• Which response do the T lymphocytes affect?

  cell mediated response