Defence System SAQs.docx

The Human Defence System SAQs - What is immunity?  1. the ability of an organisms to fight infection  - Define the function of the general defence system. 1. The general defence system is a non-specific first line of defence against foreign molecules. - What does the general defenc...

The Human Defence System SAQs - What is immunity?  1. the ability of an organisms to fight infection  - Define the function of the general defence system. 1. The general defence system is a non-specific first line of defence against foreign molecules. - What does the general defence system consist of? a. It consists of the skin/ enzymes/ clotting (platelets)/ mucous/ cilia/ acid  - Define the function of the specific defence system. 1. The specific defence system is the second line of defence specific to one antigen and involves an antigen-antibody response with specialised white blood cells. - What does the specific defence system consist of? a. It consists of lymphocytes/ monocytes/ interferons/ inflammation  - What is active immunity?  1. When the body produces its own antibodies.  - Which type of immunity provides long term immunity, active or passive?  1. Active immunity  - Which type of immunity provides short term immunity?, active or passive? A. Passive immunity - What is natural passive immunity? Give example  1. Natural passive immunity occurs when antibodies are passed from mother to her child. It takes place in the womb or when she breast feeds.  - What is artificial active immunity? 1. Artificial active immunity involves injecting or ingesting small doses of the antigen which stimulates the body to produce the antibody. - Give an example of artificial active immunity A. Injection of a vaccine. - What is a vaccine?  1. an injection of a dead or deactivated microbe that stimulates an antibody response to produce long term immunity. - Differentiate between B-Lymphocytes and T- Lymphocytes  1. B-lymphocytes mature in the bone marrow, T- lymphocytes mature in the thymus gland/ B- lymphocytes produce antibodies, T-lymphocytes don't produce antibodies  - What is the function of the killer T cell?  1. Killer T cells destroy the abnormal body cells  - What is the function of the memory T cell?  1. Memory T cells remember the antigen to prevent infection by the same pathogen.  - What is the function of the suppressor T cell? - What is the function of the helper T cell? a. **Helper T Cells** recognise the antigen and stimulate the production of killer T cells.