Pete Sewell Lesson Aim How the body defends itself against disease. In this lesson you will look at the mechanisms for defence which the body has developed to prevent bacteria and other organisms using this warm and moist environment as a host. Also looked at is the way the skin and blood behave when the body is cut, as well as the role of white blood cells.
Some consideration is given to examining the likely causes of infection and how it spreads.
At a Higher Level, candidates are expected to understand the process of clotting and that of acquiring immunity. You should be able to give a good account of the conditions under which diseases are spread. Food Contact Sewage Other organisms Poor health Water Try to remember at least three of these. Higher Candidates - you must understand the process of acquiring immunity. The human body is the perfect environment in which small organisms, such as microbes, can rapidly breed because it is warm and moist.