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Membranes of pre-synaptic and post-synaptic neurons play an important role in transmission of nerve impulses. Explain the principles of synaptic transmission. (8marks)

Synapse is the gap between two adjacent neurons in which neurotransmitters are released. Arriving action potential depolarises pre-synaptic membrane. This causes voltage gated calcium channels in membrane to...
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Answered by Alla K. • Biology tutor
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Draw the structure of a cell membrane (6 marks).

I would draw a diagram showing the structure of a cell membrane and explain each of the parts:The cell membrane is composed of a phospholipid bilayer which is composed of a hydrophilic head and a hydrophobic...
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Answered by Pravir M. • Biology tutor
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Describe the cardiac cycle in the human heart

The human heart beats around 60-100 beats per minute. Blood enters the right atrium via the superior vena cava and the inferior vena cava, the blood moves through the tricuspid valve into the right ventricle...
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Answered by Shane D. • Biology tutor
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How does an electrical impulse travel from one neuron to the next (IB-SL 6.5)?

The arrival of an action potential at the synaptic knob opens calcium ion channels in the pre-synaptic membrane and Ca++ flow in from the synaptic cleft 2. Ca++ cause vesicles of neurotransmitters to fuse wi...
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Answered by Adam K. • Biology tutor
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List five (5) risk factors for coronary heart disease, and briefly outline a piece of evidence for each one (5)?

(Chapter: further human physiology) Factor + explanation (1 point for each) for coronary heart disease (CHD):-Genetics: CHD tends to run in some families-Age: CHD is a disease of old age-Gender: men are more...
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Answered by Dimitrios K. • Biology tutor
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