Human Body Systems

Practice past-paper questions

Practise O/L exam questions on Human Body Systems with worked solutions

1. 2021 · Paper II · 6 marks
   Describe how food is digested in the human digestive system. In your answer include: (i) The organs where digestion occurs and the enzymes involved. (ii) The role of villi in the small intestine. (iii) One feature of the circulatory system that transports digested nutrients to body cells.
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   (i) Mouth — salivary amylase breaks starch to maltose. Stomach — pepsin (protease) digests proteins in acidic conditions. Small intestine — pancreatic amylase, lipase (fats → fatty acids + glycerol), protease complete digestion. (ii) Villi greatly increase the surface area of the small intestine for absorption. They have a rich blood capillary network and a lacteal (lymph vessel) for fat absorption. (iii) Blood plasma carries dissolved nutrients (glucose, amino acids) via blood vessels to all body cells.
   Source: NIE O/L Science 2021 Paper II Q8

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