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How is an action potential formed when the neurone is stimulated?

When the neurone is stimulated , the Na+ channels open to allow influx of sodium ions down its electrochemical gradient. This makes the inside of the cell less negative. When threshold voltage (-55mV) is rea...
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Answered by Ismael C. • Biology tutor
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Which component of the vaccine stimulates an immune defence? How do they prevent people from catching the disease e.g. mumps?

inactive pathogens white blood cells produce antibodies these antibodies can be then quickly released whrn the immune system comes into contact with the live pathogen and destoy it
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Answered by Ines R. • Biology tutor
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Does water travel up or down the concentration gradient?

Via osmosis, water travels down the concentration gradient to an area of lower water concentration and higher concntration of other substances.
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Answered by Jenny R. • Biology tutor
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What is the definition of osmosis? How is it different from diffusion?

Osmosis is the net movement of water molecules from a high water potential to a low water potential through a semi-permeable membrane. It is different from diffusion as it is through a semi-permeable membran...
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Answered by Coral B. • Biology tutor
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name 3 organelles that are present only in plant cells

cell wall, vacoule, chloroplasts
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Answered by Sagar S. • Biology tutor
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