(a(i))[3]
Describe the principal characteristics of a virus.
(a(ii))[2]
The human immunodeficiency virus (HIV) multiplies inside white blood cells and destroys them. Using your knowledge of what white blood cells do, suggest why the virus is called the immunodeficiency virus.
(b(i))[2]
HIV leads to AIDS. The virus can be passed on during sexual intercourse. State two methods that may be used to control the spread of HIV through sexual intercourse.
(b(ii))[2]
HIV may also be passed on in other ways. State two methods, apart from sexual intercourse, by which HIV may be transmitted.