Antigen presenting cell/Phagocyte presents antigens on its cell surface (1); receptors on some T cells match/fit these antigens (1); this activates other T cells to divide rapidly to form clones (f; these clones can form memory cells / kill infected
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How does humoral immunity work?
When a foreign antigen enters the blood there will be a B cell that has a complementary antibody for that antigen on its surface (1). B cells can act as antigen presenting cells and must be activated by T helper cells (1). Activated B cells divide by
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Why is it not possible to vaccinate against flu?
The flu virus constantly mutates and changes antigens - showing antigenic variability. We are unlikely to meet the same strain twice so memory cells produced have no effect. Therefore the body must keep producing a primary response each time.
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Use of monoclonal antibodies?
Pregnancy kits, cancer treatment, immunoassay etc.
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Two features of a successful vaccination program?
No harmful side effects and having most of the population vaccinated (herd immunity)
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What is herd immunity?
Where a large proportion of the population is vaccinated so the few individuals that cannot be vaccinated due to being immunocompromised etc are protected.
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Ethical considerations for vaccine programmes?
Animal testing - is the cost of harm to animals greater then the benefit to humans?
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How do lysosomes work?
They migrate to the phagosome and fuse with it. They then release digestive enzymes which hydrolyse the pathogen
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