Cambridge IGCSE · Analysis & Prediction

2025 Cambridge IGCSE Science - Combined (0653) Past Paper: Analysis & Answers

A comprehensive assessment of the October/November 2025 examination series for IGCSE Combined Science (0653). This analysis covers Papers 12, 22, 32, 42, 52, and 62, detailing the distribution of marks across Biology, Chemistry, and Physics. It provides a syllabus-aligned breakdown, highlights student performance issues highlighted by the examiner reports, and offers strategic preparation pathways for upcoming sessions.

Updated: Jun 13, 2026

AnalysisSample paper
Difficulty 3.2/5
Total marks
160
Duration
180 mins
Most tested
—

Paper breakdown

Paper 2: Multiple Choice (Extended): 40 marks · 45 minsPaper 4: Theory (Extended): 80 marks · 75 minsPaper 6: Alternative to Practical: 40 marks · 60 mins

Examiner insights

Official report

Common pitfalls

  • Failure to perform unit conversions: Candidates do not convert mass in grams to kilograms when calculating gravitational potential energy.
  • Misinterpreting command words: Answering 'State' with overly long, convoluted paragraphs while failing to write precise definitions.
  • Unprecise scientific vocabulary: Using general terminology like 'particles vibrating and moving' without mentioning collision frequency in enzyme reactions.

Misconceptions

  • Believing that heat energy transfers through space via conduction or convection; ignoring the requirement of a material medium.
  • Assuming a captive breeding programme only serves to house endangered animals, without referencing reproduction and reintroduction strategies.

Where marks are lost

  • Incorrect stoichiometry when balancing the chemical equation of photosynthesis.
  • Failing to subtract the blank mass when determining the net density of a measured liquid.
  • Neglecting to draw the correct double bond pattern for outer shell electrons in covalent dot-and-cross CO2 diagrams.

Estimated grade boundary

Updated: Jun 13, 2026

Source: Cambridge IGCSE grade thresholds (official)
GradeMarkPercentage
A*151/20076%
A125/20063%
B99/20050%
C74/20037%
D64/20032%
E54/20027%
Official grade boundaries published by Cambridge IGCSE grade thresholds (official).

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