Figure 13 shows three organisms that live in pond water - Edexcel - GCSE Biology - Question 7 - 2023 - Paper 2

The surface area to volume ratio is calculated using the formula:

$\text{Surface Area to Volume Ratio} = \frac{\text{Surface Area}}{\text{Volume}}$

Substituting the values for species B:

• Surface Area = 9000 μm²
• Volume = 6000 μm³

Thus,

$\text{Ratio} = \frac{9000 \text{ μm}^2}{6000 \text{ μm}^3} = 1.5 \text{ μm}^{-1}$

The surface area to volume ratio for species B is 1.5 μm⁻¹.