In GCSE Science, the requirements for keeping healthy is one of the topics looked at. This is the last of six quizzes on that subject and it looks in particular at strains of bacteria which are resistant to antibiotics - otherwise known as 'superbugs'.
Antibiotics have been in use since a team, led by scientists Howard Florey and Ernst Chain, worked out how to produce penicillin in useful quantities. Since then penicillin and other antibiotics, like amoxycillin and flucloxacillin, have saved countless millions of lives.
Unfortunately, owing to the over-use and unnecessary use of these amazing chemicals, bacteria have started to appear that are resistant to antibiotics. One of the best known is MRSA. This strain of bacteria is also resistant to other antibiotics and so is a problem in hospitals. The British press decided to call bacteria resistant to antibiotics 'superbugs' and this nickname stuck.
[readmore]MRSA isn't the only bacteria resistant to antibiotics - many more superbugs are appearing and the antibiotics that used to kill them no longer work. This is worrying because if all bacteria become resistant, we will be back to the days before penicillin was discovered. But scientists are not just sitting back and letting this happen. They are producing new antibiotics that are able to kill the resistant strains.
How do resistant bacteria arise in the first place? In any population of organisms, there is variation. This variation could produce a few bacteria that are resistant. This could be caused by a mutation or by a gene contained in the bacteria that has been there for a long time. These survive the antibiotic and can go on to reproduce so that eventually, only the resistant strain exist. If someone taking antibiotics does not complete the course, the most resistant bacteria will not be killed. These can then reproduce and create even more bacteria that can resist the effects of antibiotics.
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You can find more about this topic by visiting BBC Bitesize - Infection and response
An easy start! Antibiotics are usually specific to certain groups of bacteria
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The usual example is MRSA
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MRSA is resistant to the penicillin family of antibiotics (and some others too)
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Natural selection ensures that only the resistant or most resistant bacteria survive a course of treatment
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Resistance in bacteria is nothing to do with how big they are
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You may have been tempted by the answer chromosomes. Chromosomes are made from genes and certain genes can give a bacteria resistance to certain antibiotics
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The antibiotic kills off the least resistant bacteria first and you start to feel well again. If you don't complete the course, the most resistant bacteria could survive. If they escape from your body and infect other people who do the same as you, a completely resistant strain could develop
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Resistant bacteria will survive a course of antibiotic and therefore be able to reproduce with less competition. As future generations of bacteria inherit this resistance, diseases become more difficult to control
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Doctors no longer prescribe antibiotics for minor infections. When your own immune system deals with the bacteria, it does not rely on antibiotics, so both resistant and non-resistant bacteria are destroyed
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Exam and test tip: Were you one of the ones who worked out all 4 words first? Hat's off, you are a high flyer! But you don't really need to get all of the missing words. You can narrow it down to two answers by considering just the first word. So when answering questions, especially multiple choice, use techniques like this to make them seem less daunting
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