A person eats a meal at 0 minutes. From 120 minutes to 180 minutes the person goes for a run.
The table shows the concentrations of glucose, insulin and glucagon in the person's blood.
Table
| Time in minutes | 0 | 60 | 120 | 180 |
|---|---|---|---|---|
| Blood glucose in mg/100 cm3\text{mg}/100\ \text{cm}^3mg/100 cm3 | 90 | 140 | 95 | 70 |
| Insulin in arbitrary units | 10 | 45 | 15 | 5 |
| Glucagon in arbitrary units | 20 | 8 | 18 | 40 |
Which statement explains the change in the glucagon concentration between 120 minutes and 180 minutes?
Insulin concentration falls, so glucagon is made from insulin to raise blood glucose concentration.
Muscles use glucose in respiration, so glucagon is released to convert glucose into glycogen.
Blood glucose concentration rises, so glucagon is released to make cells take up more glucose.
Muscles use glucose in respiration, so glucagon is released to convert glycogen into glucose.
72 exam-style questions on OCR GCSE Biology 3.3 Maintaining internal environments, covering 3.3.1 Importance of a constant internal environment, 3.3.2 The skin and body temperature, 3.3.3 Insulin and blood sugar, 3.3.4 Glucagon and blood sugar, 3.3.5 Type 1 and type 2 diabetes, 3.3.6 Osmotic changes in body fluids, 3.3.7 Kidneys and water balance, 3.3.8 Structure of the kidney and tubule, 3.3.9 ADH and kidney tubule permeability, and 3.3.10 Responses to temperature and osmotic challenges. Each one has a worked solution and a mark scheme showing where the marks go.