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What are reflexes and how do they work?

Reflexes are quick and automatic reactions to harmful stimuli. Reflexes are important as they protect the body from harm. We don’t have to learn reflexes because they occur automatically from the moment we a...
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Answered by Suzi L. Biology tutor
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What are neurones?

Neurones are the specialised cells that make up the nervous system. Bundles of neurones are known as nerves. Neurones carry electrical impulses around the entire body.
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Answered by Suzi L. Biology tutor
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Describe the two components of the nervous system.

The nervous system is made up of two parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is made up of the brain and the spinal cord. The PNS is made up of sensory and mo...
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Answered by Suzi L. Biology tutor
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How does the release of calcium ions regulate muscle contraction?

Tropomyosin is a protein that covers the actin binding site. This prevents a cross-bridge forming between the myosin and actin filaments whilst the muscle is at rest. Calcium ions bind to troponin molecules,...
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Answered by Emily T. Biology tutor
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How does a high cholesterol diet increase the risk of coronary heart disease?

High cholesterol diets lead to high cholesterol levels in the blood. Low density lipoproteins, known as LDLs or BAD-cholesterol, build up in the artery walls. They form solid plaques which narrow the artery....
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Answered by Emily T. Biology tutor
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