Gce Model Questions Vol1 2025 Biology Question 34

A desert plant exhibits three separate adaptations that each affect its total water loss (\(W\)). Baseline values are: leaf area \(A = 100\ \text{cm}^2\), stomatal density \(D = 200\ \text{stomata\,mm}^{-2}\), and water loss per stomata \(r = 0.5\ \mu\text{mol\,s}^{-1}\). Total water loss is approximated by \(W = A \times D \times r\) after converting area to mm² (1 cm² = 100 mm²). The adaptations are: (i) leaf area reduced to \(40\ \text{cm}^2\); (ii) stomatal density reduced to \(80\ \text{stomata\,mm}^{-2}\); (iii) cuticle thickness reduces \(r\) to \(0.1\ \mu\text{mol\,s}^{-1}\). Assuming the other two parameters remain at baseline for each adaptation, calculate the percentage reduction in \(W\) for each case and identify which adaptation provides the greatest reduction.