DEFENDING 0.0 / 5 ? BiologyMicrobes and diseaseGCSEAQA Created by: LAUREN.FCreated on: 15-05-16 20:08 How do pathogens make you feel ill? Pathogens produce toxins/damage cells. 1 of 12 Why did it take a long time for others to accept the ideas of Semmelweis? No one knew about bacteria and viruses. 2 of 12 How are many pathogens prevented from entering the body? The skin stops pathogens entering, also mucus, stomach acid. 3 of 12 How do white blood cells defend the body? They ingest pathogens, produce antibodies, produce antitoxins. 4 of 12 What is meant by 'vaccination'? Injection/oral drops of dead or inactive pathogen to stimulate the white blood cells to produce antibodies. 5 of 12 How to antibodies 'recognise' antigens? By their shape. 6 of 12 Why are antibiotics only able to kill bacteria? Viruses are inside body cells. 7 of 12 Why do some pathogens spread rapidly? Very few people are immune to the new pathogen and no effective treatment is available. 8 of 12 How does natural selection cause resistant populations of bacteria to develop? Antibiotics kill the non-resistant strains which allows the resistant strains to survive and multiply (no competition). 9 of 12 Why do industrial laboratories use 35 degrees instead of 25 degrees as in schools? The bacteria will grow at a faster rate. 10 of 12 How do you make sure that unwanted microorganisms do not contaminate a pure culture of bacteria? Heat/sterilise all equipment, boil solutions, cover Petri dishes or flasks. 11 of 12 Look at the plate. How do you know if the bacteria have been killed by the antibiotic? There is a clear are around the filter paper disc. 12 of 12
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