Question 1
Figure 1 shows a diagram of mucus‑producing goblet cells and ciliated epithelial cells in the airways of the lungs.
(Source: © K.K.T Madhusanka/Shutterstock)
Figure 1
Describe how pathogens are removed from the airways by ciliated epithelial cells.
(2)
During a race, athletes respire aerobically and anaerobically.
Figure 2 shows an athlete after a race.
Explain how aerobic respiration provides energy for running.
(2)
The rate of respiration of maggots was investigated using the equipment shown in Figure 3.
State the reason why the soda lime is placed in the test tube.
(1)
The drop of liquid in Figure 3 is at 20 mm.
The drop of coloured liquid moved at a mean rate of 2 mm per minute.
Draw, on Figure 4, the new position of the bubble after the five minutes.
(1)
The investigation was repeated with two maggots.
Explain how the movement of the drop of coloured liquid would be affected if the investigation was repeated using fewer maggots.
(2)
State one way this investigation can be improved to obtain more reliable results.
(1)