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At P on Figure 3, the pressure in the left ventricle is increasing - AQA - A-Level Biology - Question 3 - 2020 - Paper 1
Question 3
At P on Figure 3, the pressure in the left ventricle is increasing. At this time, the rate of blood flow has not yet started to increase in the aorta. Use evidence f... show full transcript
Worked Solution & Example Answer:At P on Figure 3, the pressure in the left ventricle is increasing - AQA - A-Level Biology - Question 3 - 2020 - Paper 1
Step 1
Use evidence from Figure 3 to explain why.
Answer
At point P, the aortic valve is closed due to the pressure in the aorta being higher than in the left ventricle. As such, the increasing pressure in the left ventricle does not lead to an increase in blood flow to the aorta. The valve must open for blood flow to occur, which does not happen until the pressure in the ventricle exceeds that in the aorta.