Question 18N.3.SL.TZ0.2
| Date | November 2018 | Marks available | [Maximum mark: 4] | Reference code | 18N.3.SL.TZ0.2 |
| Level | SL | Paper | 3 | Time zone | TZ0 |
| Command term | Calculate, Explain, Suggest | Question number | 2 | Adapted from | N/A |
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.
Calculate the ventilation rate at rest, giving the units.
[1]
12 breaths per minute/6 litres per minute ✔
breaths per minute.
Accept answers from 5.5 to 6 litres per minute.
Answer must include breaths or litres and a standard unit of time.
Correct:
eg: 12 breaths / minute
eg: 0.1 L sec–1 or 6 L min–1
Incorrect:
eg: but 12 breaths = 0 marks
Explain the changes in ventilation after 35 seconds.
[2]
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 ✔
Suggest how the total lung volume at rest would differ for a patient with emphysema.
[1]
«total resting lung volume» would be greater ✔