Outline one way in which antiviral drugs work.

Discuss two difficulties associated with solving the AIDS problem.

Any one of:
alter cell’s genetic material so that virus cannot use it to multiply  [✔]

prevent viruses from multiplying by blocking enzyme activity within host cell
OR
inhibit the synthesis of viral components by blocking enzymes inside the cell [✔]

prevent viruses from entering «host» cell
OR
bind to cellular receptors targeted by viruses
OR
bind to virus-associated proteins/VAPs which target cellular receptors
OR
prevents removal of protein coat/capsid
OR
prevents injection of viral DNA/RNA into cell [✔]

prevent/hinder the release of viruses from the cell [✔]

Note: Accept “prevents synthesis of virus by host cell”.

Accept “alters RNA/DNA/genetic material of virus”.

Do not accept just “mimics nucleotides”.

Any two of:
viruses lack cell structure so difficult to target with drugs  [✔]

HIV is a retrovirus
OR
HIV genetic material is in the form of RNA instead of DNA [✔]

HIV affects/destroys helper/T-cells which are necessary to fight infection [✔]

HIV has great genetic diversity so difficult to produce «a» vaccine [✔]

anti-retroviral agents are expensive so not everyone/country can afford them [✔]

socio-cultural issues deter people from seeking treatment/prevention/diagnosis
OR
lack of education/conversation/stigma associated with being HIV-positive [✔]

mutation of virus/HIV [✔]

virus/HIV metabolism linked to that of host cell [✔]

drugs harm host cell as well as virus/HIV [✔]

HIV difficult to detect/remains dormant [✔]

Candidates responded fairly well to this question. Candidates who did not receive a mark were either too vague or discussed anti-bacterial methods.

Most candidates were awarded at least one of the two marks possible for this question. Some student responses were too vague or discussed the social and political issues surrounding the AIDS crisis. There were also some responses, which only talked about AIDS extensively with no mention of the virus.