Name: _______________________________________________ 	

  	
  	
Topic 1 Lifestyle, health and risk	

 	
Date:	

  	
  	
Time:  27 minutes	
  	
Total marks available:  27	
  	
Total marks achieved: ______ 	

  	

  	

  	

  	

  	

  	

  	
Data analysis focus 	

	

Questions

Q1.  The diagram shows a section of a human heart and blood vessels.

A scientist investigated the volume of blood pumped by the heart of a healthy individual.
The graph shows the volume of blood measured in the left ventricle.

(i)  Calculate the heart rate.
(2)

Answer ........................................................... beats min−1
(ii)  Calculate the volume of blood, in dm3, pumped by the left ventricle each minute.
(3)

Answer ........................................................... dm3
Q2.  Obesity is a risk to health.
There is a drug called Orlistat that can help obese people to lose weight. This drug works by permanently attaching to the enzyme lipase.
Two studies, A and B, were carried out to investigate the effectiveness of the drug.
In study A, 20 people were given different concentrations of the drug and the fat content of their faeces was measured. The graph below shows the results.

Results of study A

(a)  Analyse the data in the graph to explain how the drug helps obese people to lose weight.
(5)
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(b)  Study B was a placebo-controlled study. The change in body mass of 300 patients was measured over a period of 18 months. The graph below shows the results.

Results of study B

Explain how the data in study B show that the design of study B is better than the design of study A.
(4)
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(c)  (i)  A high body mass index (BMI) is an indicator of obesity. Use the formula for BMI to calculate the height of a person with a mass of 80 kg and a BMI of 31.25.
(3)

Answer ...........................................................
(ii)  The table shows the percentage decrease in the BMI of 350 people who took the placebo and a group of 350 people who took the drug daily for a period of 12 months.

Give one reason why the percentage of people with a decrease in BMI is higher than the percentage of people with a decrease in body mass.
(1)
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(iii)  Explain the health risks of having a very high BMI.
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  (Total for question = 18 marks)

Q3.  The photograph shows the tropical rattlesnake, Crotalus durissus terrificus.

This snake produces a toxin called convulxin (CVX), which activates platelets leading to blood clotting.
The effect of CVX on the rate of thrombin production was investigated.
The graph shows the concentration of thrombin in a sample of blood treated with CVX.

(i)   Calculate the rate of thrombin production during the last two minutes of this investigation.
(2)

 Answer ........................................................... 
(ii)  State and justify a suitable control for this investigation.
(2)
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(Total for question = 4 marks)
Q1.
No Examiner's Report available for this question

Q2.
No Examiner's Report available for this question

Q3.
 
(i)
This was a relatively straight-forward question requiring candidates to extract two numbers from the graph and use them to calculate a rate. A significant number gave an answer which was a rate per 2 minutes. It was disappointing to see that a large number of candidates either did not state a unit or did not give a correct unit.

Results Plus: Examiner Comments
This is an example of a response which scores full marks. The candidate extracts the correct data from the graph. They perform the correct calculation to get the answer of 125. They also adapt the units from the graph to write the correct unit.

Results Plus: Examiner Comments
This is an example of an answer which gain 1 mark for the correct answer but does not give the correct unit. Therefore the second mark is not awarded.

Results Plus: Examiner Tip
If the answer line does not give a unit then it is always a good idea to write the correct unit next to your answer.

Results Plus: Examiner Comments
This is an example of an answer where the candidate gives a unit in addition to the correct answer. However, they do not give the correct unit as they have written 'mol' instead of 'nmol'. Hence they score only 1 mark.

Results Plus: Examiner Tip
Always make sure you copy information correctly.

(ii)
This question highlighted that many candidates are confused between a control and a controlled variable. Many candidates described ways that variables such as temperature should be controlled instead of understanding that in order to see if CVX had any effect on thrombin production they needed to compare the results with blood that had not been treated with CVX.

Results Plus: Examiner Comments
This is an example of a response where the candidate has confused control with controlled variables.

Results Plus: Examiner Comments
This is not a suitable control and therefore scores 0 marks.

Results Plus: Examiner Comments
This response correctly identifies a suitable control for this investigation and explains that it would provide a comparison

 

Mark Scheme

Q1.

 

Q2.

Q3.