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Explain how a vaccination prevents infection.

A vaccine causes white blood cells to produce anitbodies. Antibodies are proteins which kill pathogens, such as viruses and bacteria. If the body is reinfected by the same pathogen as the vaccine then the wh...
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Answered by Tomas C. • Biology tutor
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What is a reflex action and along which pathway does it travel in the nervous system?

A reflex action is an automatic rapid involuntary response, which acts to protect the body from damage. Such as when you touch something extremely hot, you involuntarily remove your hand from the hot object....
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Answered by Isobel R. • Biology tutor
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What is an enzyme?

An enzyme is known as a biological catalyst. This is because they can speed up reactions by providing an alternative pathway, lowering the activation energy of the reaction. They are normally composed of a p...
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Answered by Liam M. • Biology tutor
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Please explain Mitosis

Background knowledge DNA - carry the genetic code that determines characteristics of an organism Chromosomes - made from long DNA molecules, many genes all coiled up into a chromosome. A healthy person will ...
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Answered by Jacob C. • Biology tutor
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Why is the heart known as a double pump?

The heart is known as a double pump becasue each half pumps blood around a different circulation system. The right side pumps blood to the lungs, while the left side pumps blood around the body.
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Answered by David H. • Biology tutor
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