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Explain how sound is perceived by the ear, including the roles of the eardrum, bones of the middle ear, oval and round windows, and the hair cells of the cochlea.

· Sound travels as pressure waves in the air which push the membrane of the eardrum, causing it to vibrate. The degree of vibration will vary according to the frequen...

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Explain how a nerve impulse passes along a non-myelinated neuron.

Generation of a Resting Potential

▪ The sodium-potassium pump (Na⁺/K⁺ pump) maintains the electrochemical gradient of t...

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Explain the relationship between the structure and function of arteries, capillaries and veins.

Arteries have a thick outer layer of longitudinal collagen and elastic fibers to avoid leaks and bulges. They have a thick wall, which is essential to withstand the high pressures.

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Outline the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline).

The heart muscle can contract by itself, without the stimulation of a nerve. This is called myogenic muscle contraction.

The region that initiates each contraction is found in the wa...

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Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria.

Antibiotic resistance in bacteria is a common problem. It results from the transfer of a gene that gives resistance to a specific antibiotic usually by means of a plasmid to a bacterium. Some bacteria...

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