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15 Cards in this Set
- Front
- Back
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What are the main differences between a bacterial cell and a plant cell?
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A bacterial cell has a plasmid, DNA is not in a nucleus and it has a flagellum
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What is meant by the nuclear zone?
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The nuclear zone is the place where tightly coiled DNA is found
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What are the functions of ribosomes and plasmids?
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Ribosomes are involved in protein synthesis and plasmids are circular pieces of DNA
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What is the function of the flagella?
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It is a long projection that helps them to move
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How do bacterial cells obtain energy?
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They can obtain energy form sunlight or from feeding on organic and inorganic substances
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Explain how bacteria reproduce
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By binary fission, which is asexual reproduction (no variation)
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What makes a good micro organism to use commercially?
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Produce the substance needed in large amounts in a short period of time.
They must be genetically stable, grow rapidly, not be harmful to humans and feed on cheap materials. Better if they dont need high temperatures. |
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Give some examples of micro organisms used in biotechnology
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Yeast is used to make beer, bread and alcohol.
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Explain how pathogens can gain entry to the body
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By air e.g. measles, by contaminated food and water e.g. cholera, by direct contact e.g. smallpox, by exchange of body fluids e.g. HIV and by insect bites e.g. malaria
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What factors affect the pathogenicity of bacteria?
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The way the bacteria attaches itself to host cells, the type of toxins the bacteria produces, the number of bacteria needed to cause infection and the ability of the bacteria to spread throughout the body
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Explain the effect of exotoxins and endotoxins.
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Exotoxins are proteins which are secreted or leaked from bacteria.
Endotoxins are complex compounds which cause and effect in the host only when the bacteria dies. |
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What affect do Endotoxins have on the body?
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When the bacteria dies the endotoxin is engulfed by a phagocyte, it causes weakness, aching and high temperature.
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Discriminate against HIV and Aids.
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HIV is the infection and Aids is the disease.
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Why is the HIV virus such a problem?
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It hides inside helper T cells, the immune system can't recognise it and when it breaks out it destroys the cell and the immune system is lowered.
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How is HIV transmitted?
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By transfusion of infected blood, sharing needles and sexual activity.
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