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2. Clostridium tetani is a bacterium that can be found in soil - Edexcel - GCSE Biology Combined Science - Question 2 - 2019 - Paper 1
Question 2
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... show full transcript
Worked Solution & Example Answer:2. 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 who are vaccinated against tetanus have developed immunity to the disease. The vaccination stimulates their immune system to produce antibodies specific to the tetanus toxin, which is produced by Clostridium tetani. Therefore, if the bacteria enter through a cut, the immune system can quickly recognize and neutralize the toxin before it can cause illness. Additionally, vaccines often lead to the formation of memory cells, ensuring a rapid response to any future exposure.
Step 2
Explain how these bacteria have become resistant to Colistin.
Answer
Some bacteria have become resistant to Colistin through a variety of mechanisms. One common way is through genetic mutations that occur during replication, resulting in changes that reduce the drug's effectiveness. Additionally, bacteria can acquire resistance genes from other bacteria through horizontal gene transfer, a process that allows them to share genetic material. Continuous exposure to Colistin, due to incomplete treatment courses or overuse, can also promote the selection of resistant strains that survive and proliferate.