O-LevelBiologyHuman Nutrition5090/21 · Oct/Nov 2020 · Q110 Marks

The diagram represents what the human alimentary canal would look like if it was removed from a person and straightened out. Gastric (stomach) by-pass surgery is sometimes used to help a person to lose weight. The diagram shows the result of this type of surgery.

(a)(i)Identify the parts A, B, C and D labelled on the diagram. A B C D[4]
(a)(ii)State which part has the absorption of water as its main function.[1]
(b)(i)The digestion of one food substance is most likely to be affected by this surgery. State which food substance and explain your answer. food substance explanation[2]
(b)(ii)Suggest how this surgery may help a person to lose weight.[3]

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Mark scheme

Marking points from the official mark scheme (Oct/Nov 2020). The mark or mark type is shown in brackets.

[1] A oesophagus / gullet;
[1] B duodenum / ileum / small intestine ;
[1] C colon / large intestine ;
[1] D rectum;
[1] colon / large intestine / C ;
[1] protein;
[1] explanation: pepsin / protease / acid / muscular stomach mixing contents / mechanical digestion / chemical digestion ;
[1] stomach smaller AW ;
[1] stomach holds less food;
[1] reduced appetite / not hungry / feels full AW ;
[1] food + less eaten / less digestion / less absorption / lower intake of energy ;
[1] energy used greater than energy taken in ;

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