DRUGS
ANTIBIOTIC RESISTANCE
MRSA
● Methicillin-resistant Staphylococcus aureus is a group of
gram-positive bacteria that are genetically distinct from
other strains of Staphylococcus aureus.
● MRSA is responsible for several difficult-to-treat infections
in humans.
● It caused more than 100,000 deaths attributable to
antimicrobial resistance in 2019
Explain how using antibiotics only when essential can
limit the development of resistant bacteria such as
MRSA
The correct answer is B (a substance taken into the body that modifies or affects
chemical reactions) because:
Drugs always have their effect at a chemical level, by affecting chemical reactions
in cells, tissues and organs.
A is incorrect because not all drugs are addictive or harmful; many have beneficial
effects, though most would be harmful if taken at an excessive level (an
'overdose').
C is incorrect because not all drugs are plant extracts (some come from fungi and
some are manufactured in a laboratory), and not all of them kill bacteria.
D is incorrect because not all drugs produce side effects, though many do.
The correct answer is C because:
Antibiotics are only effective against bacteria.
A is incorrect because sometimes, bacteria can survive antibiotics but if they
cannot reproduce, this is effectively the same as death because of their short
reproduction lifecycles.
B and D are incorrect because antibiotics are only effective against bacteria.
The correct answer is C because:
Antibiotics do not work on viruses. Viruses insert their genetic material inside
cells, the antibiotic doesn’t work inside cells. Antibiotics work on bacteria by
either killing them or stopping or slowing their growth.
All the other answers are correct for antibiotics. Some of them are produced
by fungi, including the first antibiotic penicillin, which is made in Nature by the
fungus Penicillium notatum. These fungi produce the antibiotic to give them
resistance to bacteria.
A patient should always finish the course once they have started taking them
for an infection, in order to ensure that all the pathogenic bacteria are dead.
The correct answer is A because:
Viruses are technically not living cells, this means that they are not
affected by antibiotics. Viruses do not have cell walls or carry out cellular
functions. Antibiotics work by disrupting cell chemical reactions or the
production of cell walls.
B is incorrect because viruses do not contain cytoplasm, and antibiotics
don’t affect cytoplasm.
C is incorrect because penicillin does not work on viruses.
D is incorrect because this is correct as viruses use the host cell to
reproduce rapidly. It is not relevant to why penicillin will not work on
viruses, however.
The correct answer is C (1 and 4) because:
When an individual fails to complete an antibiotic course their body is less
likely to clear the bacterial infection so there is more opportunity for resistance
to evolve in the bacterial population. Antibiotics should never be used to treat
viral infections as they are ineffective against viruses.
A is incorrect because antibiotics are vital for patient survival when they are
suffering from serious bacterial infections.
B is incorrect because 4 has not been included in the answer.
D is incorrect because both 2 and 3 represent ways in which antibiotics
should be used in order to minimise antibiotic resistance.
The correct answer is B (liver) because:
The liver is the primary site for drug metabolism.
A is incorrect because although the stomach is involved in the
digestion of some oral medications it does not fully
metabolise the drug.
C and D are incorrect because the brain and kidneys are not
the primary sites of drug metabolism.
The correct answer is D (1, 2 and 4) because:
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Statement 1 is correct because farmers often protect their whole herd by using
antibiotics, to prevent the spread of disease, even when none of the animals are
sick. This practice is now not in use widely as it encourages antibiotic resistance
Statement 2 is correct because if a person stops taking antibiotics before the end
of the course, some pathogens may still be alive in their body, but not in sufficient
numbers to cause symptoms. If antibiotics are stopped, these few bacteria can
multiply freely, produce high levels of toxins and cause the disease to reappear in
that individual
Statement 4 is correct because the definition of antibiotics is that they work
against bacteria only (not other types of microorganism)
Statement 3 is incorrect because antibiotics are used routinely, with care, very
effectively against bacterial infections.