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Question 18N.3.HL.TZ0.d

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Date November 2018 Marks available [Maximum mark: 2] Reference code 18N.3.HL.TZ0.d
Level HL Paper 3 Time zone TZ0
Command term Outline Question number d Adapted from N/A
d.
[Maximum mark: 2]
18N.3.HL.TZ0.d

Measurements of the lung capacity of a student were recorded using a spirometer and displayed with a data logger. Initially the student was at rest, then changed to carrying out strenuous exercise. The results are displayed in the graph.

Outline the function of pneumocytes in the lungs.

[2]

Markscheme

a. type I pneumocytes carry out gas exchange ✔ 
OWTTE

b. type II pneumocytes secrete surfactant/fluid OWTTE
OR
type II pneumocytes create a moist surface inside the alveoli
OR
type II pneumocytes reduce surface tension between alveoli
OR
type II pneumocytes prevent the sides of the alveolus adhering to each other ✔

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