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Describe how phagocytosis of a virus leads to presentation of its antigens (3 marks)

Virus engulfed by phagocyte (broad immune response), destroyed using lysosomes (hydrolysis) and viral antigens presented on cell membrane (trigger specific immune response e.g. anti-bodies). Steps of phagocy...
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Answered by Ben J. • Biology tutor
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Describe the function of enzymes DNA helicase and DNA polymerase during DNA replication (2 marks)

DNA replication occurs in two phases: DNA separation (DNA helicase) and DNA transcription (DNA polymerase) Enzyme Function: 1. DNA helicase – (unwinding DNA and) breaking hydrogen bonds between DNA strands (...
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Answered by Ben J. • Biology tutor
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What is the sequence of events for muscle contraction?

· The myosin head attaches to the myosin binding site on the actin filament forming an actinomyosin bridge · ATP is hydrolysed to ADP and inorganic phosphate as the cross-bridge forms (ATP hydrolase is activ...
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Answered by Letisha B. • Biology tutor
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How do I convert the following, 0.089, into standard form?

Your final answer should consist of a number between 1 and 10 multiplied by 10 to the power of a particular number. This particular number we will call x. We begin by noting that 0.089 is required to become ...
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Answered by Beth A. • Maths tutor
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How does insulin contribute to the regulation of blood glucose control?

When high levels of glucose are detected in the blood, for example after a big meal, insulin is released from beta cells in the Islet of Langerhans. These are clusters of cells present in the pancreas. Insul...
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Answered by Leah C. • Biology tutor
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