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Discuss the incompleteness of the fossil record and the resulting uncertainties about human evolution.

Incompleteness of the Fossil Record ▪ Fossilisation is an exceptionally rare occurrence that requires an unusual combination of special conditions ▪ Most living things tend to decompose rapidly (or be scaven...
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Describe one example of transient polymorphism.

A polymorphism is the occurrence of two or more clearly different phenotypes within the same population of a species - it reflects the effects of more than one allele in the gene pool Transient Polymorphism ...
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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 frequency and amplitude of the sound waves. · Th...
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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 the resting potential (-70 mV) ▪ It is a membrane protein that uses active transport 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. They also have thick layer...
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