• Question: HOW ARE CERTAIN DISEASES SPREAD AND HAS BACTERIA ALWAYS EXISTED IN THE UNIVERSE

    Asked by saneaah118 to Heather, Helen, Hugh, Jane, Julian on 11 Nov 2014.
    • Photo: Julian Onions

      Julian Onions answered on 11 Nov 2014:

      Bacteria has been on the Earth for somewhere between 3.5 and 4 billion years. As far as we know we haven’t seen it anywhere else in the universe so far, so we think it started on the Earth. We might be wrong though, there is a theory called panspermia where life travelled through space to land on our planet. There is not any particularly compelling evidence for his theory so far though.

    • Photo: Helen Johnson

      Helen Johnson answered on 12 Nov 2014:

      The human-to-human spread of diseases is mostly by bodily fluids, like the droplets in coughs and sneezes, or blood. However some are genetic or spread via e.g. unhygienic preparation of food, contaminated water, insects etc… many of these aren’t contagious.

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