DP Biology (last assessment 2024)

Test builder »

Question 18N.3.SL.TZ0.b

Select a Test
Date November 2018 Marks available [Maximum mark: 2] Reference code 18N.3.SL.TZ0.b
Level SL Paper 3 Time zone TZ0
Command term Explain Question number b Adapted from N/A
b.
[Maximum mark: 2]
18N.3.SL.TZ0.b

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.

Explain the changes in ventilation after 35 seconds.

[2]

Markscheme

a. the volume of air per breath increases
OR
the volume of each breath reaches a maximum/levels off
OR
frequency of ventilation/breaths per minute increases ✔

b. exercise increases «rate of cellular» respiration/energy use/blood CO2/acidity ✔

c. exercise causes increased demand for oxygen/removal of carbon dioxide ✔

d. maximum rate/depth of ventilation is determined by the capacity of the student ✔

Syllabus sections