Smallpox, measles and HIV/AIDS are infectious diseases caused by different viruses. These different viruses share some structural features.

Mark scheme

Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.

1. [1] I ref. to features that are absent e.g. no cellular structure
2. [1] any one from
3. [1] nucleic acid core ;
4. [1] either DNA or RNA ; I ref. to, single / double, stranded
5. [1] protein coat / capsid ;
6. [1] A idea of (outer covering) made of capsomeres
7. [1] (smallpox) Variola ;
8. [1] (measles) Morbillivirus ;
9. [1] allow, virus / viruses, for Morbillivirus
10. [1] allow, virus / viruses, for Morbillivirus
11. [1] I penicillin doesn't act on viruses
12. [1] any two from
13. [1] 1 penicillin only acts on bacteria (and measles is caused by a virus); A prokaryotes
14. [1] 2 Morbillivirus does not have, cell walls / murein / peptidoglycan ;
15. [1] 3 Morbillivirus does not have, transpeptidases / the enzyme that is inhibited (by penicillin); A idea of not possessing the enzyme that is acted upon by penicillin
16. [1] 4 Morbillivirus does not grow / penicillin (only) acts on growing cells / AW ; A when cell wall is, growing (larger) / getting bigger
17. [1] 5 Morbillivirus does not have cellular structure / Morbillivirus is acellular/ penicillin only acts on cells ;
18. [1] to treat / to cure / may have / prone to / to prevent / AW, infectious diseases / infections / AW ; e.g. bacterial / opportunistic / secondary, disease(s) / infection(s) A to kill bacterial pathogens
19. [1] A to treat (some) fungal diseases
20. [1] R viral disease / HIV infection
21. [1] do not award if a mix of viral and bacterial diseases stated
22. [1] allow ref. to, cheaper / low cost, related to relevant mp once only
23. [1] any four from
24. [1] did not mutate to max 2
25. [1] 1 same vaccine could be used (everywhere / for many years) ; A no need to manufacture different vaccines in context of ease of, administering / planning / production
26. [1] 2 (so) a person was protected for, a long time / life / each exposure (to virus) ; AW e.g. same virus so vaccinated person did not become ill on repeated exposure A reduced / no, risk of vaccine becoming ineffective A long-lasting immunity once only for mp2 or mp4 I more effective vaccine
27. [1] 3 no, research / trials / development, required for new vaccine(s); in context of pre-mass production
28. [1] live and closely related to max 2
29. [1] 4 (closely related so) same antigens / (gives the desired) immune response / antibodies produced / memory cells produced / memory cells remain ; A long-lasting immunity once only for mp4 or mp2
30. [1] 5 live virus (replicates, so), gives a strong(er) immune response ; A better immunity than inactive virus R natural active immunity
31. [1] 6 no need for boosters ;
32. [1] 7 ref. to not smallpox virus, so fewer health and safety issues (at all stages of development and use) ; e.g. could not get ill from smallpox A not smallpox virus so more people willing to have vaccine
33. [1] thermostable vaccine
34. [1] 8 longer shelf-life / doesn't degrade easily / other advantage ; e.g. no refrigeration needed could be easily, stored / transported no wastage
35. [1] easy to administer
36. [1] 9 (using non-medical staff) increased number of people vaccinated / percentage cover / herd immunity ; allow idea of faster delivery of vaccination programme A idea that (makes vaccine) more accessible to people in developing countries
37. [1] one mark for correct completion of table ;
38. [1] active immunity | ✔
39. [1] artificial immunity | ✔
40. [1] natural immunity | X
41. [1] passive immunity | X