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What is a reflex and what do you mean by a reflex arc? (both "reflex" and "reflex arc" are on the CCEArevised GCSE Biology specification)

1. A reflex is an automatic response to a stimulus . For example: If I touch a hot plate, my hand will automatically pull away from the heat. Another example is the pupillary light reflex. If you turn on a l...
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Answered by Michael M. • Biology tutor
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Briefly describe how the autonomic nervous system returns internal body temperature to normal following a rise in body temperature

Body temperature in mammals is controlled and maintained by a small part of the brain called the hypothalamus. Information about the temperature both inside and outside of the body is detected by thermoregul...
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Answered by Chantal R. • Biology tutor
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How and why does an increase in temperature effect the rate of an enzyme substrate reaction?

As temperature increases up to the optimal temperature for the enzyme, the rate of reaction will increase at a steady rate because the kinetic energy of the enzyme and substrate molecules increases, so there...
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Answered by Edward S. • Biology tutor
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How is heart rate controlled?

It can be controlled by hormonal or neuronal (from the nervous system) input. To increase the heart rate, during a fight or flight situation for example, adrenaline may be released from the adrenal glands an...
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Answered by Grace M. • Biology tutor
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Explain the series of events at a synapse between 2 neurons.

An impulse travels along the pre-synaptic neurone, and when it reaches the axon ending it stimulates calcium channles to open on the pre-synaptic membrane. This allows calcium ions to rush into the neurone c...
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Answered by Jim L. • Biology tutor
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