Exercise, medical technology and ethicsEdexcel A-Level Biology A: Subtopic test

1. 1
   A cohort study followed 20 000 adults aged 40 to 60 for ten years. Of the participants who took more than 150 minutes of moderate exercise per week, 5.0 % developed type 2 diabetes. Participants who took less than 60 minutes per week were 2.4 times more likely to develop type 2 diabetes. The less active group also had a higher average body mass index and ate more processed food.

   (a)

   What percentage of the less active group would be expected to develop type 2 diabetes?

   [1 mark]

   • A7.4 %
   • B2.4 %
   • C12 %
   • D120 %

   (b)

   Which of the following is a confounding variable in this study?

   [1 mark]

   • AThe amount of processed food eaten
   • BThe ten-year length of the study
   • CThe number of participants
   • DThe age range of 40 to 60

   (c)

   Explain why this study cannot prove that a lack of exercise causes type 2 diabetes.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A 24-year-old footballer tears the anterior cruciate ligament in his knee. His surgeon repairs it using keyhole (arthroscopic) surgery rather than open surgery. A teammate who had a lower leg amputated after a road accident now competes in running events using a carbon-fibre prosthetic blade.

   (a)

   Which is an advantage of keyhole surgery compared with open surgery for the footballer?

   [1 mark]

   • AIt needs no specialist equipment
   • BSmaller incisions cause less tissue damage, so recovery is faster
   • CIt removes any risk of infection
   • DIt gives the surgeon a direct, unrestricted view of the whole joint

   (b)

   Which statement about the teammate's prosthetic blade is correct?

   [1 mark]

   • AIt is identical to a natural leg in sensation and control
   • BIt never needs repair or replacement
   • CIt removes any need for rehabilitation
   • DIt restores function so that a person with a disability can take part in sport

   (c)

   Explain how keyhole surgery can allow an injured athlete to return to sport sooner.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A study compared 500 marathon runners with 500 non-running volunteers matched for age. In the two weeks after the marathon, 30 % of the runners reported symptoms of an upper respiratory tract infection (a cold or sore throat). In the control group, 12 % reported these symptoms over the same two weeks.

   (a)

   Calculate how many times greater the number of runners with symptoms was than the number of control volunteers with symptoms.

   [3 marks]

   (b)

   Evaluate the conclusion that running a marathon suppresses the immune system.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A national sports federation is reviewing its policies. It is considering whether athletes should be allowed to use performance-enhancing substances such as anabolic steroids and erythropoietin (EPO) under medical supervision, and it is also considering how medical technology such as keyhole surgery and prostheses is changing who can take part in elite sport.

   (a)

   Discuss whether the use of performance-enhancing substances by athletes is ethically acceptable.

   [6 marks]

   (b)

   Evaluate how keyhole surgery and prostheses enable people with injuries and disabilities to take part in sport, and discuss one limitation or issue of each.

   [6 marks]

   Total for question 4: 12 marks

End of questions