Biology 5090 · O Level · Human gas exchange

Human gas exchange — practice question

A man chooses to start fitness training so that he can improve how well oxygen is supplied to his muscles.
(a(i))[4]

Describe the path taken by an oxygen molecule as it moves from the atmosphere to the muscles.

(a(ii))[2]

The fitness training is intended to bring about changes in the man's body. Suggest two body changes that would improve his ability to supply oxygen to his muscles.

(b(i))[2]

State the chemical process in muscles that uses oxygen to release energy.

(b(ii))[1]

Use the graph to find the maximum volume of oxygen the man uses in one minute.

(b(iii))[3]

The graph indicates that the man can push his exercise intensity beyond the point where maximum oxygen consumption has been reached, but only for a short time. Explain why.

(b(iv))[2]

After four weeks of fitness training, the man measures his oxygen consumption again. On the graph, sketch a line to show the expected results of successful fitness training.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: Air passes in through the nose/nasal passages and then enters the larynx/trachea

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