A scientist compares oxygen diffusion into fish eggs in two groups. The eggs are from the same species, their coverings have the same permeability, and both groups are kept at the same temperature. The embryos use oxygen for aerobic respiration.
The table shows mean measurements taken at the start of the investigation.
| Group | Surface area of egg (mm²) | Oxygen concentration in surrounding water (mmol dm⁻³) | Oxygen concentration just inside egg covering (mmol dm⁻³) | Thickness of egg covering (mm) |
|---|---|---|---|---|
| A | 20 | 0.30 | 0.12 | 0.040 |
| B | 15 | 0.28 | 0.16 | 0.060 |
Calculate the ratio of the initial rate of oxygen diffusion into an egg in group A to the initial rate into an egg in group B.
102 exam-style questions on Edexcel GCSE Biology 8.1 Exchange surfaces and diffusion, covering 8.1.1 Introduction to exchange and transport, 8.1.2 Alveoli adapted for gas exchange, 8.1.3 Factors affecting rate of diffusion, and 8.1.4 Rate of diffusion using Fick's law. Each one has a worked solution and a mark scheme showing where the marks go.