1[3 marks]
Explain how insulin controls blood glucose concentration after a meal.
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- the pancreas secretes insulin into the blood (1)
- insulin causes cells to take up glucose from the blood (1)
- the liver converts glucose into glycogen for storage (1)
- so blood glucose concentration falls to normal (1)
- Max 3
2
Higher tier
[3 marks]Explain how glucagon increases blood glucose concentration.
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- glucagon is secreted by the pancreas when blood glucose is low (1)
- glucagon acts on the liver (1)
- the liver changes glycogen into glucose (1)
- glucose is released into the blood (1)
- Max 3
3[4 marks]
Describe the causes of type 1 diabetes and type 2 diabetes and how each is controlled.
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- type 1: the pancreas does not produce enough insulin (1)
- type 1 is controlled by insulin injections (1) allow monitoring blood glucose and controlling carbohydrate in the diet
- type 2: body cells no longer respond to insulin (1)
- type 2 is controlled by diet and exercise / weight loss (1) allow medication
4[3 marks]
A woman has a mass of 72 kg and a height of 1.60 m. Her waist is 88 cm and her hips are 100 cm. (a) Calculate her BMI. Give your answer to 1 decimal place. (2) (b) Calculate her waist:hip ratio. (1)
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- (a) height squared = 1.60 × 1.60 = 2.56 (1)
- BMI = 72 ÷ 2.56 = 28.1 (1) allow 28.125
- (b) 88 ÷ 100 = 0.88 (1)
5
[3 marks]
The table shows practice figures for the percentage of adults with type 2 diabetes in three BMI groups. Evaluate the evidence that a higher BMI causes type 2 diabetes.
| BMI group | Adults with type 2 diabetes (%) |
|---|---|
| Below 25 | 2 |
| 25 to 29.9 | 6 |
| 30 and above | 15 |
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- as BMI increases the percentage with type 2 diabetes increases / positive correlation (1) allow use of figures
- a correlation does not prove that high BMI causes diabetes (1)
- other factors, such as diet, exercise or age, may be involved / BMI does not show fat compared with muscle (1)