The diagram shows part of the human alimentary canal and its associated organs. F H

Mark scheme

Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.

1. [1] (top) oesophagus / gullet;
2. [1] (middle) duodenum / small intestine ;
3. [1] (bottom) gall bladder;
4. [1] digestion / break down food or protein / protein to polypeptides / protein to amino acids ;
5. [1] (mechanical) muscle / contractions / movement + make food particles smaller / chyme ;
6. [1] (chemical) enzymes / proteases / pepsin + proteins ;
7. [1] hydrochloric acid + optimum pH AW ;
8. [1] hydrochloric acid + destroy microbes / defence against microbes ;
9. [1] mucus + protects lining / lubrication ;
10. [1] pancreas;
11. [1] control of blood glucose concentration / level or produces / releases + insulin / glucagon;