The table below lists different regions in the world arranged in order from the warmest to the coldest, along with the average body mass of adult red foxes found in each region:
ClimateLocationAverage mass of a red fox (kg)warmestSaudi Arabian Desert3.2\cline2−3↓North Africa3.8\cline2−3Central Europe5.5\cline2−3Northern Sweden7.2\cline2−3coldestSiberia8.5\begin{array}{|c|l|c|} \hline \textbf{Climate} & \textbf{Location} & \textbf{Average mass of a red fox (kg)} \\ \hline \text{warmest} & \text{Saudi Arabian Desert} & 3.2 \\ \cline{2-3} \downarrow & \text{North Africa} & 3.8 \\ \cline{2-3} & \text{Central Europe} & 5.5 \\ \cline{2-3} & \text{Northern Sweden} & 7.2 \\ \cline{2-3} \text{coldest} & \text{Siberia} & 8.5 \\ \hline \end{array}Climatewarmest\cline2−3↓\cline2−3\cline2−3\cline2−3coldestLocationSaudi Arabian DesertNorth AfricaCentral EuropeNorthern SwedenSiberiaAverage mass of a red fox (kg)3.23.85.57.28.5Use your understanding of natural selection to suggest why the red foxes in Siberia have the largest average mass.
66 exam-style questions on Edexcel IGCSE Biology Inheritance. Each one has a worked solution and a mark scheme showing where the marks go.