9700_s26_qp_24 — 2026 May-June Biology 9700 Question Paper 2 Variant 4 · Cambridge CAIE AS & A Level

Confusing similar scientific terms with very different meanings

“Pairs of similar scientific terms with very different meanings were sometimes confused. For example, some candidates mixed up antibiotics and antibody, antibodies and antigens, and introns and exons.”— Paper 2, March 2023

How to fix: Make flashcards for commonly confused pairs: antibody/antigen, antibiotic/antibody, intron/exon, gene/allele, centromere/centrosome, primary transcript/mRNA, collagen molecule/collagen fibre, smooth muscle/elastic tissue. Test yourself by defining each without looking.

Using 'water concentration' instead of 'water potential' in osmosis

“Candidates should use the terms 'water potential' and 'water potential gradient'. The terms 'water concentration' and 'water concentration gradient' are not appropriate.”— Paper 2, March 2025

How to fix: Always write 'water potential' (never 'water concentration'). Water moves from higher water potential to lower water potential. A more negative water potential means lower water potential. Pure water has a water potential of zero.

Imprecise membrane naming — saying 'membrane' instead of the specific membrane

“Candidates should be clear when referring to a specific membrane. If it is the membrane that surrounds the cell, it must be referred to as a cell surface membrane.”— Paper 4, May/June 2023

How to fix: Always specify WHICH membrane: 'cell surface membrane' (not just 'membrane'), 'inner mitochondrial membrane', 'thylakoid membrane', 'presynaptic membrane', 'postsynaptic membrane', 'tonoplast'. Just saying 'membrane' is too vague to earn marks.