PSLE Science 2026: The Complete Topic Checklist

One of the biggest challenges in preparing for PSLE Science is knowing what to study. The MOE syllabus covers topics from P3 all the way to P6, and it can be hard to know which ones will appear in your exam and how much depth you need. This checklist covers every topic in the PSLE Science syllabus, organised by theme, with key concepts for each. Use it to audit your knowledge and plan your revision.

How to use this checklist: Go through each topic and ask yourself, "Can I explain this concept in a full sentence using the correct scientific vocabulary?" If yes, tick it off. If no, it goes on your revision list. Be honest with yourself — partial knowledge often leads to partial marks.

How PSLE Science is Structured

PSLE Science tests knowledge and skills from the following levels:

• P3 — Diversity, Plants, Animal Life Cycles, Fungi and Bacteria, Materials, Light, Heat, Magnets
• P4 — Plant Reproduction, Human Digestive System, Matter and Changes of State, Electrical Systems, Forces
• P5 — Cells REMOVED 2026, Reproduction in Plants and Animals, Respiratory System, Transport System, Water Cycle, Adaptation and Survival, Food Chains and Food Webs, Matter (Particle Model)
• P6 — Cells REMOVED 2026 and Organisation, Reproduction, Respiratory and Transport Systems (continued), Genetics and Heredity (basic concepts)

The five themes that organise all these topics are: Diversity, Systems, Cycles, Interactions, and Energy.

Theme 1: Diversity

Diversity questions ask you to classify, compare, and explain the differences between living things and materials. This theme appears in almost every PSLE paper.

• Living vs Non-Living vs Once-Living — MRS GREN (Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition); all 7 must be present; common traps (fire, robots, dormant seeds)
• Vertebrates — 5 groups (fish, amphibians, reptiles, birds, mammals); distinguishing features of each; warm-blooded vs cold-blooded; examples and common traps (bat = mammal, whale = mammal, frog = amphibian)
• Invertebrates — insects (6 legs), arachnids (8 legs), crustaceans (>8 legs), myriapods, molluscs, echinoderms; identifying by number of legs and body parts
• Materials and Properties — transparency (transparent/translucent/opaque); electrical conductivity; heat conductivity; solubility; density (float/sink); hardness; waterproofing; choosing suitable materials and justifying the choice

Theme 2: Systems

Systems questions test your understanding of how organs or components work together. The digestive, respiratory, and transport systems are particularly high-priority.

• Plant System — roots (anchor + absorb water and minerals), stem (transport + support), leaves (photosynthesis + transpiration), flowers (reproduction); xylem and phloem; stomata; adaptations of leaves for photosynthesis
• Photosynthesis — word equation; raw materials, energy source, and products; conditions needed; where it happens (chloroplasts/chlorophyll); what happens without each condition; leaf adaptations; starch test with iodine; variegated leaves
• Human Digestive System — all organs in order (mouth → oesophagus → stomach → small intestine → large intestine → rectum → anus); role of each organ; enzymes (amylase, pepsin, protease, lipase); bile (not an enzyme — emulsifies fat); villi; absorption vs digestion
• Electrical Systems — series vs parallel circuits; conductors and insulators; factors affecting bulb brightness; open vs closed circuits; switches; drawing and interpreting circuit diagrams
• Respiratory System (P5) — organs (nasal passage, trachea, bronchi, bronchioles, alveoli, lungs); the role of each; how oxygen enters the blood; what happens during exercise; difference between breathing and respiration
• Transport System (P5) — heart, blood vessels (arteries, veins, capillaries); blood components and functions; double circulation; how nutrients and oxygen are transported; anaemia

Theme 3: Cycles

Cycles questions test your ability to describe, explain, and connect the stages of natural recurring processes.

• Animal Life Cycles — complete metamorphosis (Egg → Larva → Pupa → Adult); incomplete metamorphosis (Egg → Nymph → Adult); examples of each; comparison table; frog life cycle (Egg → Tadpole → Froglet → Adult); moults; chrystalis vs cocoon
• Plant Life Cycles — pollination (self vs cross); fertilisation; seed dispersal methods (wind, water, animal, explosion); germination conditions (water, warmth, air); vegetative propagation methods
• The Water Cycle — evaporation, transpiration, condensation, precipitation, collection/runoff; changes of state involved; role of the Sun; human impacts (deforestation, urbanisation); Singapore's water supply
• Matter and Changes of State — 3 states; particle model; melting, freezing, evaporation, condensation, boiling, sublimation; melting/boiling points of water (0°C and 100°C); expansion and contraction; separating mixtures (filtration, evaporation, magnetic separation, sieving)

Theme 4: Interactions

Interactions questions are among the most analytical at PSLE — they ask you to trace cause-and-effect relationships through ecosystems and physical systems.

• Food Chains and Food Webs — arrow direction (energy flow); producers, primary/secondary/tertiary consumers; decomposers; what happens when a species is removed; energy loss at each level (10% rule); biodiversity; population effects
• Adaptations — structural, behavioural, physiological; desert adaptations (camel features); arctic adaptations (polar bear, penguin); aquatic adaptations (fish, dolphin); rainforest adaptations; feature → function → survival benefit format
• Magnets — 4 magnetic materials (iron, steel, nickel, cobalt); non-magnetic metals; like poles repel, unlike attract; poles are strongest; non-contact force; Earth's magnetic field; compass; demagnetisation methods
• Forces — gravity, friction, elastic (spring force), magnetic force, contact vs non-contact forces; effects of forces on objects (change shape, speed, direction); balanced and unbalanced forces; measuring force with a spring scale

Theme 5: Energy

Energy questions ask you to explain how energy is transferred, transformed, and its practical implications.

• Heat Energy — heat always flows from hot to cold; thermal equilibrium; conductors and insulators; expansion and contraction; thermometers; applications (cooking, building insulation, clothing); dark vs light surfaces
• Light Energy — light travels in straight lines; sources vs reflectors; transparent/translucent/opaque; shadows (umbra/penumbra); reflection; how we see objects; the Sun as the primary source of light energy on Earth
• Electrical Energy — covered under Electrical Systems (Theme 2) — series vs parallel; converting electrical energy to other forms (light, heat, sound, motion)