Question 21M.2.SL.TZ2.6c
| Date | May 2021 | Marks available | [Maximum mark: 5] | Reference code | 21M.2.SL.TZ2.6c |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Describe | Question number | c | Adapted from | N/A |
Describe the risk to the human population of indiscriminate use of antibiotics.
[5]
a. antibiotics block bacterial processes ✔
b. example of bacterial process ✔ e.g. cell wall formation
c. variations exist naturally in a population / some are naturally resistant to the antibiotic ✔
d. bacteria that are not resistant to this antibiotic will die / only resistant will survive (when antibiotic given) ✔
e. this characteristic could be passed to next generation ✔
f. (natural selection) leads to changes in the proportions/frequency in the population ✔
g. human population will be exposed to antibiotic resistant bacteria and will not have antibiotic to kill them ✔
h. (antibiotic resistant bacteria) may pass resistance to other bacteria species/types by means of plasmids (so other bacteria species turn resistant too) ✔
(attempted by about 60 % of the cohort)
Part (a) was a departure from the 'draw a prokaryote' type of question that has appeared numerous times. In general, it was well answered. There were some good diagrams as answers which clearly showed only the prokaryotic characteristics. Part (b) asked for an explanation of the production of antibodies. Many weaker students wrote at length about non-specific phagocytosis which was not credited. Weaker students confused antibodies and antigens and even talked about antibiotics. This question was designed to be answered by the Standard Level students using Standard Level material. Some tried to include HL material and became very confused. Part (c) was really a question about Darwin's theory of evolution set in context. Many of the answers were very Lamarckian with the antibiotic causing the mutation, instead of some bacteria already having resistance. Better students opened with comments and an explanation that antibiotics only kill bacteria.
