During a cave rescue, a rescuer hears loose rock falling and must pull rapidly on a rope. The table shows estimated measurements for blood supplied to the rescuer's arm muscles before and after adrenaline is released.
| Condition | Blood flow to arm muscles (cm³ min⁻¹) | Blood glucose concentration (mg cm⁻³) |
|---|---|---|
| Before adrenaline is released | 80 | 0.80 |
| After adrenaline is released | 400 | 1.20 |
Calculate the factor by which the rate of glucose delivery to the arm muscles increases after adrenaline is released.
Explain how adrenaline causes the higher blood glucose concentration and how both changes shown help the arm muscles contract rapidly.
89 exam-style questions on Edexcel GCSE Biology 7.1 Hormones and coordination, covering 7.1.1 Endocrine glands and hormone transport, 7.1.2 Adrenalin and fight or flight, and 7.1.3 Thyroxine and negative feedback. Each one has a worked solution and a mark scheme showing where the marks go.