(a(i))[1]
Describe the change that will occur in the upper box containing air as a person takes one breath in from the apparatus.
(a(ii))[3]
State the percentage of oxygen in atmospheric air, and explain how the oxygen percentage in the air in the upper box will alter as a person breathes in and out through the apparatus several times.
(a(iii))[1]
Substance M is included in the apparatus so that it absorbs an excretory product from expired air. Name this excretory product.
(b(i))[3]
Explain how the action of one named muscle brought about the part of the chart labelled N.
(b(ii))[1]
A second chart was produced for one minute by the same person after vigorous exercise. State how an increased breathing rate after exercise would appear on this second chart.