specific

• specific 


  B cells

  T cells
• lymphocytes 


  white blood cells that help defend the body against specific pathogens
• t helper cells 


  contain receptors which respond to a single antigen
• t killer cells 


  kill abnormal cells and body cells that are infected by pathogens
• B lymphocytes 


  produced in bone marrow

  has a specific receptor on its surface

  when activated its receptor binds to antigen with a complementary shape

  activated B cells secrete antibodies
• T lymphocytes 


  produced in bone marrow but mature in thymus gland

  have a specific receptor on its surface

  2 types: T helper cells, T killer cells