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Clostridium tetani is a bacterium that can be found in soil - Edexcel - GCSE Biology Combined Science - Question 2 - 2019 - Paper 1
Question 2
Clostridium tetani is a bacterium that can be found in soil. It causes the infection tetanus. Children are vaccinated against tetanus. Explain why these children do... show full transcript
Worked Solution & Example Answer:Clostridium tetani is a bacterium that can be found in soil - Edexcel - GCSE Biology Combined Science - Question 2 - 2019 - Paper 1
Step 1
Explain why these children do not get tetanus if the bacteria enter their body through a cut in the skin.
Answer
Children vaccinated against tetanus are given a vaccine that helps their immune system recognize and fight the toxin produced by the bacteria. When they come into contact with Clostridium tetani, their immune system has already developed antibodies that neutralize the toxin, preventing the onset of tetanus disease. Furthermore, vaccination helps by stimulating the production of memory cells, which ensure a faster and more effective immune response upon future exposures.
Step 2
Explain how these bacteria have become resistant to Colistin.
Answer
Bacteria can develop resistance to Colistin through several mechanisms. One way is through natural selection; when exposed to Colistin, bacteria that have a mutation that allows them to survive despite the antibiotic are more likely to reproduce. Over time, these resistant bacteria become more prevalent in the population. Additionally, the bacteria may acquire genes from other resistant bacteria, leading to genetic variation that confers resistance. This can occur through horizontal gene transfer, where genetic material is exchanged between bacteria.