Question 1
Which statement describes the circulatory system?
- A pump and valves only
- Blood vessels, a pump and valves that ensure one-way flow of blood
- Blood vessels and a pump that allow blood to flow in both directions
- A pump that moves blood and air
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Answer: B (1) Vessels, pump and valves for one-way flow
Question 2
(a) Name the pump of the circulatory system. [1] (b) State the job of valves in the circulatory system. [1]
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- heart (1)
- stop blood flowing backwards / ensure one-way flow of blood (1)
Question 3
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe the single circulation of a fish.
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- blood is pumped from the heart to the gills (1)
- then flows to the body / organs (1)
- then returns to the heart / passes through the heart once per circuit (1)
Question 4
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe the double circulation of a mammal, starting with blood leaving the right ventricle.
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- right ventricle pumps blood to the lungs (1) allow via pulmonary artery
- blood returns to the left atrium (1) allow via pulmonary vein
- left ventricle pumps blood to the body (1) allow via aorta
- blood returns to the right atrium (1) allow via vena cava
Question 5
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanExplain the advantages of a double circulation compared with a single circulation.
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- blood returns to the heart after the lungs (1)
- so can be pumped again / pressure is increased (1)
- blood reaches body at high pressure so substances are delivered faster (1)
- lower pressure in the lungs does not damage capillaries (1)
- mammals have a high (metabolic / respiration) rate so need fast oxygen supply (1)
- Max 3