Define the term prophylaxis.

Name the four categories of materials used for preparing vaccine.

Correct the following statements if they are false (without changing the first word).

1. DDT is an antiseptic.
2. Penicillin is a disinfectant.
3. Disinfectants are applied on the body.
4. Deodorants are both antiseptic as well as disinfectant.
5. Alexander Fleming discovered the first sulphonamide.
6. Antibiotics cannot be made synthetically.
7. Sulphonamides are now rarely used.

List any three uses of antibiotics.