Biology 9700 · AS & A Level · The heart

The heart — practice question

Fig. 6.1 shows a sectional diagram of a mammalian heart.
(a)[1]

Identify the blood vessel marked X.

(b)[3]

Explain why the muscle walls of the left and right ventricles differ in thickness.

(c)[1]

Name the heart structure that functions as the pacemaker and starts the cardiac cycle.

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This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Either the superior vena cava or the inferior vena cava” …

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