Biology no. 1

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Theories of Evolution

Scientists estimated life began on Earth about 3 billion years ago

Book 1: 1 1.8 Changing Pathogens Some bacteria develop resistance to antibiotics so should use antibiotics properly, bacteria have natural mutation that means they aren't affected by the antibiotics. These mutations happen by chance producing new strains of bacteria by natural selection. More types of bacteria are becoming resistant to antibiotics making them more difficult to treat, over years antibiotics have been overused and used when they aren't really needed increases in rate at which antibiotic-resistant strains are being developed.

Antibiotic-resistant strains:

Normally antibiotic kills bacteria of non-resistant strains though individual resistant bacteria survive and reproduce so population of resistant bacteria increases. Antibiotics no longer used to treat non serious infections like mild throat infections which are often caused by viruses hopefully will slow down rate of development of resistant strains.

The process below occurring multiple times for different antibiotics means that bacteria develops resistance to many antibiotics

To prevent more resistant strains of bacteria appearing must no overuse antibiotics, don't use them to treat viral infections as uneffective. Some antibiotics treat very specific bacteria others treat a lot right bacteria must be used to treat each bacterial infection to prevent further antibacterial resistance occurring. Must also finish course of medicine.