Risk factors for cardiovascular diseaseEdexcel International A Level Biology: Mind map

Exam questions on Risk factors for cardiovascular disease

1. A hospital clinic measures the concentrations of lipoproteins in patients' blood to assess their risk of cardiovascular disease (CVD).
   Explain why a high concentration of HDL in the blood reduces the risk of CVD.2 marks
2. Researchers are investigating whether dietary antioxidants such as vitamin C reduce the risk of CVD. In a laboratory practical, students compare the vitamin C content of fruit juices by seeing how much of each juice is needed to decolourise a fixed volume of DCPIP solution.
   A student finds that 2.5 cm³ of orange juice decolourises 1.0 cm³ of DCPIP solution, whereas 4.0 cm³ of apple juice is needed. Deduce which juice contains the higher concentration of vitamin C and explain your answer.2 marks
3. A study followed 4,000 men for ten years. Men with a total blood cholesterol concentration below 5 mmol dm⁻³ had 15 cases of coronary heart disease (CHD) per 1,000 men per year. Men with a concentration between 5 and 6.5 mmol dm⁻³ had 25 cases per 1,000 per year, and men above 6.5 mmol dm⁻³ had 45 cases per 1,000 per year. The men in the highest cholesterol group were on average three years older and more of them smoked.
   Describe the relationship between blood cholesterol concentration and CHD shown by the data, and calculate how many times greater the rate of CHD is in the highest cholesterol group than in the lowest group.3 marks