(i)     State the name of one disease caused by each.

Bacteria:

Viruses:

(ii)     Discuss the differences between bacteria and viruses.

Describe two misuses of antibiotics that have led to some bacteria becoming resistant.

It is much more difficult to produce effective antiviral drugs than drugs that kill bacteria. Describe two ways in which antiviral drugs work.

(i)     Bacteria:

tuberculosis/TB / syphilis / cholera / salmonella / bronchitis / botulism / lyme disease / (stomach) ulcers / anthrax / diptheria / meningitis / MRSA / gonorrhea / chlamydia / septicaemia;

Viruses:

influenza / common cold / AIDS / herpes / rabies / small pox / polio / rubella / yellow fever / measles / mumps / encephalitis / chicken pox / shingles / mononucleosis;

Do not accept name of an organism (such as e-coli) rather than a disease.

(ii)     bacteria larger than viruses / viruses are smaller than bacteria;

bacteria are cells / viruses comprise DNA in a protein coat;

bacteria have cell wall/nucleus/cytoplasm / viruses do not have cell components;

bacteria can reproduce without a host / viruses require host/cell for replication/reproduction;

bacteria are not always harmful/parasitic / viruses are always parasitic;

patient non-compliance / not completing courses / OWTTE;

overprescription;

use for animals/in animal feedstock;

Accept overuse.

Do not accept overdose.

becomes part of DNA of virus / alters virus DNA/genetic material / blocks enzyme (polymerase) which builds DNA;

changes the cell membrane so that it inhibits the virus entry/bonding to the cell;

prevents virus from leaving the cell (after reproduction);

prevents virus from using cell to multiply/reproduce/replicate;

Many candidates stated the correct name of one bacterial and one viral disease but some had problems stating differences between bacteria and viruses. Candidates must realize that AIDS is a viral disease not HIV.

In part (c), the terms “over dosage” and “over prescription” were often used interchangeably.

In part (d), the method of action of anti-viral was poorly explained. It seemed candidates, at times, learned several key phrases without clearly understanding their meaning and so used them in inappropriate context.