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How is an action potential transmitted across a synapse?

Looking at a cholinergic synapse:The action potential arrives at the presynaptic knob. This causes voltage-gated calcium ion channels to open, and calcium ions to diffuse into the presynaptic knob.The influx...
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Answered by Megan M. • Biology tutor
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Rat poison is not always an effective rodenticide and will reduce in effectiveness with age. Explain why

Any type of poison is not guaranteed to eradicate rats entirely. This is due to genetic mutations allowing an individual to be immune to certain types of toxins. Whilst the population may be eradicated, if e...
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Answered by Charles D. • Biology tutor
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Describe the theory of enzyme action.

Enzymes are biological catalysts that speed up the rate of biological reactions. The enzyme active site and the substrate are complimentary in shape. This allows the substrate to bind to the active site of t...
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Answered by Catherine D. • Biology tutor
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Outline the role of phagocytic white blood cells in defence against pathogens

Phagocytes are part of the innate immune system. They are primarily responsible for clearing extracellular infections e.g. bacteria or fungus, by recognising and ingesting the pathogen. Typically, pathogens ...
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Answered by Adeline R. • Biology tutor
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Explain how an action potential is transmitted across a cholinergic synapse.

The action potential arrives at the synaptic knob of the presynaptic neurone. The action potential stimulates the opening of voltage-gated calcium ion channels in the presynaptic neurone, allowing calcium io...
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Answered by Kathryn E. • Biology tutor
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