Evidence for evolution

    Cards (25)

    • Bacteria evolve quickly as they reproduce at a fast rate. (Double every 20 minutes).
    • Mutations cause new strains of bacteria.
    • Antibiotic resistance is when certain bacteria will no longer be killed by the antibiotic and will become resistant.
    • The 4 main stages in the development of antibiotic resistance are:

      -Random mutations occur in the genes of individual bacterial cells.
      -Some mutations protect the bacterial cell from the effects of the antibiotic.
      -Bacteria without the mutation will die or cannot reproduce when the antibiotic is present.
      -Resistant bacteria can reproduce with less competition from normal bacteria strains.
    • MRSA is so dangerous as it is resistant to most antibiotics..
    • The number of MRSA strains increase.
    • This has resulted in more infections that are difficult to control.
    • Three measures that can prevent the development of antibiotic resistance:
      -complete full course of antibiotics.
      -Only take them when needed.
      -Stop using them in farming.
    • The first antibiotic was created in 1928 by Alexander Fleming.(Penicillin)
    • It is derived from penicillium mold.
    • Most antibiotics were discovered in the 1950s and 60s.
    • The need for new antibiotics is on the rise as more people are becoming resistant to the ones we already have.
    • Two main problems with making new antibiotics is that they are costly and take time to develop.
    • Wafarin is the active ingredient in rat poison.
    • Random mutations in the genomes of rats have caused some of them to become resistant to them.
    • The number of resistant rats will increase whereas the number of non-resistant rats will decrease.
    • This is known as survival of the fittest.
    • Warfarin no longer works as more and more rats are becoming resistant to it.
    • Extinction is when a species dies out as they have not adapted well to their environment.
    • Extinction has a role in evolution as some species disappear, whilst others survive and continue to evolve.
    • 6 factors as to why some species go extinct:

      -new diseases.
      -competition.
      -new predators.
      -changes to environment.
      -a catastrophic event.(asteroid + volcano eruption)
    • Fossils show us that some species have gone extinct over time.(dinosaurs)
    • Extinction is still happening today.
    • Extinction occurs due to human activity.
    • The dodo became extinct as humans went to the island where the dodos were and they ate them. Dodos were easy to catch as prey as they could not fly.
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