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6 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is a virus?
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A pathogenic non-living substance
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Not including the fact that viruses can reproduce.
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How are viruses described
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As obligate parasites. This is because they can only reproduce if they take over another animals cell.
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Viruses often target specific cells i.e. poliomyelitis virus attacks nerve cells, hepatitis virus targets liver cells
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How small are viruses
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20-300nm (1nm = 1x10^-9 m). They can only be seen with an electron microscope.
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Spread of viruses
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Viruses can be spread by the secretion of any bodily fluid e.g. sneezing, coughing, faeces, sexual contact etc.
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Viral structure
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Viruses are composed of: one type of nucleic acid (DNA or RNA) and a protective protein coat.
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