A person with type 1 diabetes injects insulin and then goes for a long run without eating.
Their blood glucose concentration falls dangerously low.
Which statement explains why?
The injected insulin is converted into glucagon, which stores glucose as glycogen in the liver.
Exercise makes body cells stop responding to insulin, so glucose cannot enter the muscle cells.
Exercise stops the pancreas releasing glucagon, so glycogen is converted into more glucose.
The injected insulin keeps causing cells to take up glucose while muscles use more in respiration.
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.