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Date November 2020 Marks available 3 Reference code 20N.3.SL.TZ0.17
Level Standard level Paper Paper 3 Time zone TZ0 / no time zone
Command term Identify Question number 17 Adapted from N/A

Question

The table shows the origin and function of gastric secretions in the digestive system.

Identify the missing items by completing the table.

[3]
a.

Explain how Helicobacter pylori can cause stomach ulcers.

[2]
b.

Markscheme

Secretion: gastrin;
Function: digest proteins;
Secreting cells: parietal;

If more than one answer do not give the mark unless all are correct.

a.

a. H. pylori weakens/degrades the mucous coating;

b. (this) allows acid to get through to the epithelial layer;

c. the acid damages the stomach wall;

b.

Examiners report

Both parts (a) and (b) were good discriminating questions. Weaker candidates could possibly score one mark from three for completion of the table and explaining that acid damages the stomach walls. Weaker candidates said that Helicobacter pylori increased HCl production or attacked the stomach wall.

a.
[N/A]
b.

Syllabus sections

Option D: Human physiology » Option D: Human physiology (Core topics) » D.2 Digestion
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Option D: Human physiology » Option D: Human physiology (Core topics)
Option D: Human physiology

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