Scientists measured the blood flow rates to different organs of an athlete at rest and while running. The results are shown in the table below:
| Organ | Rate of blood flow at rest (mL/min\text{mL/min}mL/min) | Rate of blood flow during running (mL/min\text{mL/min}mL/min) |
|---|---|---|
| Brain | 750 | 750 |
| Heart | 250 | 1000 |
| Muscles | 1000 | 24500 |
| Kidneys | 1200 | 250 |
| Digestive tract | 1400 | 300 |
| Other organs | 400 | 200 |
| Total | 5000 | 27000 |
By how many times has the total blood flow increased during running? Give your answer to the nearest whole number.
Explain the differences in blood flow to the muscles and the digestive tract during running compared to rest.
82 exam-style questions on OCR GCSE Biology 2.1 Supplying the cell, covering 2.1.1 Transport across cell membranes, 2.1.2 Mitosis and the cell cycle, 2.1.3 Importance of cell differentiation, and 2.1.4 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.