6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Learn this properly: Structure of the HeartPriya is a competitive 800 m runner. As she races, her body must deliver large amounts of oxygen to her leg muscles and rapidly remove the carbon dioxide they produce.
Explain how Priya's cardiorespiratory system meets these increased demands during her race. In your answer refer to gaseous exchange at the alveoli, the transport of gases by the blood vessels, and at least one way the system increases supply during exercise. (6 marks)
A sports scientist records a rower's breathing at rest and during a hard ergometer effort. The data are shown below.
| Condition | Tidal volume (ml) | Breathing rate (breaths/min) |
|---|---|---|
| At rest | 500 | 14 |
| Hard effort | 2,800 | 45 |
(a) Using VE=TV×BR, calculate the rower's minute ventilation at rest and during the hard effort. Show your working and give units. (2 marks)
(b) Using the data, state which factor — tidal volume or breathing rate — has increased by the larger multiple, and support your answer with the figures. (2 marks)
Blood is carried around the body in arteries, veins and capillaries.
(a) Describe two structural differences between an artery and a vein, and explain how one of these differences suits the vessel to its function. (2 marks)
(b) State the one-cell-thick vessel where gas exchange happens in the muscles, and explain why this structural feature is important. (1 mark)
Humans have a double circulatory system.
(a) Explain what is meant by a "double" circulatory system, naming the two circuits involved. (2 marks)
(b) Identify one advantage of a double circulatory system for a games player whose muscles need a high oxygen supply during a match. (1 mark)
When a swimmer breathes in during a race, the muscles involved in inspiration contract.
State what happens to the diaphragm and to the volume of the thoracic (chest) cavity during inspiration. (2 marks)
During exercise a performer breathes more deeply, taking in a larger volume of air with each breath.
Name the lung volume that describes the amount of air breathed in or out in one breath. (1 mark)