The table below shows information about four different sizes of cubical agar blocks containing indicator, used in a laboratory experiment to model how cell size affects the rate of diffusion.
| Agar Block | Side length (mm\text{mm}mm) | Surface area (mm2\text{mm}^2mm2) | Volume (mm3\text{mm}^3mm3) | Surface area to volume ratio |
|---|---|---|---|---|
| P (Smallest) | 3 | 54 | 27 | 2 : 1 |
| Q | 5 | 150 | 125 | 1.2 : 1 |
| R | 8 | 384 | 512 | YYY : 1 |
| S (Largest) | 12 | 864 | 1728 | 0.5 : 1 |
Calculate the value of YYY in the table.
Describe the relationship between the size of the agar block and its surface area to volume ratio.
30 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.