A-LevelBiologySelection and evolutionFeb/Mar 2022Paper 4 Q88 Marks
Natural selection and artificial selection (selective breeding) both have important roles in evolutionary change. (a) Seahorses are fish with an unusual appearance and many specialised features. Fig. 8.1 shows a seahorse. [Figure 8.1] Two species of seahorse, Hippocampus erectus and H. zosterae, are found in the coastal waters of the Gulf of Mexico and the Caribbean Sea. • It is thought that these two species of seahorse have a common ancestor. • The ranges of the two species overlap in many areas. • Male and female seahorses stay together for the whole of the breeding season. • H. erectus is much larger than H. zosterae. • Few seahorses occur that are intermediate in size between the two species.
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
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