During a race, adrenaline is released into the blood of a runner. Adrenaline causes liver cells to convert glycogen into glucose. Which statement explains why this helps the runner?
More glucose reaches the muscles for respiration, so more energy is released.
More glucose is stored in the muscles as glycogen, so it can be used later.
Less glucose is in the blood, so more water moves into the muscle cells.
More glucose reaches the muscles, so they need less oxygen for respiration.
84 exam-style questions on OCR GCSE Biology 3.2 Coordination and control – the endocrine system, covering 3.2.1 Principles of hormonal coordination and control, 3.2.2 Roles of thyroxine and adrenaline, 3.2.3 Hormones in human reproduction, 3.2.4 Interactions of reproductive hormones, 3.2.5 Hormones in contraception, 3.2.6 Hormones in reproductive technologies, 3.2.7 Plant hormones in growth and coordination, 3.2.8 Effects of plant hormones, and 3.2.9 Uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.