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Explain how a vaccination can prevent an illness.

A vaccine introduces a dead or inactive pathogen such as components of a virus or bacteria. The host (the person who receives the vaccination) will develop an immune response to this pathogen. The immune res...
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Describe and explain the differences between arteries and veins.

A rteries carry blood a way from the heart, whereas veins carry blood back towards the heart.Arteries have much thicker muscular walls in comparison to veins, as they need to carry blood at high pressure fro...
CW
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How many chambers does the heart have and what are their functions?

The heart has 4 chambers: right atrium, left atrium, right ventricle and left ventricle.Right atrium - pumps blood from the Vena Cava to the right ventricle.Right ventricle - pumps blood to the lungs.Left at...
SY
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Describe the process of eating to defecation of food.

After biting off a chunk of food using our teeth, it is chewed with repetitive action of our jaw and teeth. Then with swallow reflex ,bolus of food enters our oesophagus via peristalsis and then the stomach ...
SR
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a) Compare the differences between an artery and a vein. b) List and explain 2 features that allow capillaries to exchange substances efficiently.

a) Veins have a larger lumen and a thinner wall as they carry blood at a lower pressure than the blood in arteries. Due to this low pressure, veins have valves to assist with the continuous movement of blood...
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