Question 1
In which region of the digestive system are nutrients absorbed?
- Oesophagus
- Small intestine
- Rectum
- Mouth
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Answer: B (small intestine)
Question 2
State where water is absorbed in the digestive system.
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- most in the small intestine (1)
- some in the colon / large intestine (1)
Question 3
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanExplain the significance of villi and microvilli in the small intestine.
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- increase the (internal) surface area (1)
- microvilli on the epithelial cells of each villus increase the area further (1)
- for absorption of (digested) nutrients (into the blood) (1)
- so absorption is faster / more is absorbed in a given time (1)
- Max 3
Question 4
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe the structure of a villus.
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- finger-like projection (1)
- wall is one cell thick / thin epithelium (1)
- surface cells have microvilli (1)
- network of capillaries (1)
- lacteal in the centre (1)
- Max 4
Question 5
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels mean(a) State what is absorbed into the capillaries of a villus. [2] (b) Name the vessel in the centre of a villus that absorbs the products of fat digestion, and name these products. [2]
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- (a) glucose (1)
- amino acids (1) allow vitamins / mineral ions / water
- (b) lacteal (1)
- fatty acids and glycerol (1)