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AQA Biology 2016 AS-Level Question

Hi,

I'm stuck on question 9: https://filestore.aqa.org.uk/sample-papers-and-mark-schemes/2016/june/AQA-74012-QP-JUN16.PDF

9. Table 1 shows the volume of blood in a woman’s left ventricle at different times during one second.
Table 1
Time / seconds Volume of blood in left
ventricle / cm3
0.0 112
0.1 120
0.2 95
0.3 65
0.4 50
0.5 55
0.6 82
0.7 90
0.8 100
0.9 112
1.0 120

0 9 . 1 Use Table 1 to calculate the heart rate in beats per minute.
Tick () one box next to the correct answer.
[1 mark]
60
66.7
75
85.7

0 9 . 2 The stroke volume is the volume of blood pumped out of the left ventricle during
one cardiac cycle.
Use Table 1 to determine the stroke volume.

The answer for the first one is 66.7 and the answer for the second is 70.

I'd really appreciate your help!

Thanks
Reply 1
Hi~
For 9.1, one heart beat is 1 cardiac cycle so you would look for the times where the volume of blood is the same and find the difference. In this case it is 0.9s (112cm^3) and to find the heart rate you do 1 divided by time for one beat x 60
To find stroke volume you find the difference between the maximum and minimum volume, so 120-50 is 70
Hope this helps :smile:
Reply 2
Original post by kakaoei
Hi~
For 9.1, one heart beat is 1 cardiac cycle so you would look for the times where the volume of blood is the same and find the difference. In this case it is 0.9s (112cm^3) and to find the heart rate you do 1 divided by time for one beat x 60
To find stroke volume you find the difference between the maximum and minimum volume, so 120-50 is 70
Hope this helps :smile:


thank you!!
Hello, I would like to know how do we get (112cm^3) and is it the cardiac output ?