All worksheets are free, printable A4 PDF sheets aligned to the MOE 2026 Primary Science syllabus. Each worksheet covers one PSLE topic with a mix of MCQ, True/False, structured questions and model answers. Print at home or share the link with your child's teacher.
Topics available: Forces · Food Chains · Photosynthesis · Electrical Systems · States of Matter · Living Things · Plants · Water Cycle · Animal Life Cycles · Light · Magnets · Digestive System · Respiratory System · Plant Reproduction · Environment & Ecosystems
All 15 PSLE topics in one PDF bundle. Print at home, share with your child, or use with a tuition group. Aligned to MOE 2026.
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One clean A4 sheet per topic — key definitions, study notes, and exam Q&As. Print at home, save as PDF, or share in your class WhatsApp group. All 21 topics, completely free.
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| Name the 5 groups of vertebrates (animals with a backbone). | Fish, Amphibians, Reptiles, Birds, Mammals. Remember: FAR-B-M (Fish, Amphibians, Reptiles, Birds, Mammals)! |
| What are the 3 things ALL living things need to survive? | 1. Food (nutrition) 2. Water 3. Air (oxygen). Without any one of these, they cannot survive. |
| How many legs do insects have? What are 3 examples? | Insects have 6 legs. Examples: butterfly, ant, bee, grasshopper, beetle, mosquito. |
| What is the difference between vertebrates and invertebrates? | Vertebrates HAVE a backbone (e.g. fish, frog, snake, bird, dog). Invertebrates have NO backbone (e.g. worm, insect, snail, jellyfish, spi... |
| What are the 4 main parts of a flowering plant? | 1. Root (anchor + absorb water) 2. Stem (transport + support) 3. Leaf (photosynthesis) 4. Flower (reproduction) |
| What 3 things does a plant need for photosynthesis? | Sunlight + Water + Carbon dioxide → Glucose + Oxygen. (Remember: SWC → GO!) |
| What gas do plants take IN during photosynthesis? What gas do they release? | Plants take IN carbon dioxide (CO₂) and release OXYGEN (O₂). This is opposite to what animals do! |
| What is the function of the LEAF? | The leaf is the main organ for PHOTOSYNTHESIS — making food for the plant. It is flat and broad to absorb maximum sunlight. |
| Name the 4 stages of a butterfly's life cycle. | 1. Egg 2. Larva (caterpillar) 3. Pupa (chrysalis) 4. Adult butterfly. This is COMPLETE metamorphosis. |
| What is the difference between complete and incomplete metamorphosis? | Complete: 4 stages, young looks very different from adult (butterfly, frog, housefly). Incomplete: 3 stages, nymph looks like a small adu... |
| Name 3 animals that are amphibians. | Frogs, toads, salamanders, newts. Amphibians live both on land and in water, and lay eggs in water. |
| What is the function of the PUPA stage in a butterfly's life cycle? | The pupa (chrysalis) is the TRANSFORMATION stage. Inside, the caterpillar's body reorganises into an adult butterfly. The pupa does NOT eat. |
| How are fungi DIFFERENT from plants? | Fungi cannot make their own food (no chlorophyll, no photosynthesis). They get food by breaking down dead organisms or absorbing nutrient... |
| How do fungi reproduce? | Fungi reproduce by releasing tiny SPORES. Spores float in the air and grow into new fungi when they land on a suitable surface. |
| Give 2 USEFUL and 1 HARMFUL example of fungi. | Useful: mushrooms (food), yeast (bread/baking). Harmful: mould that spoils food, athlete's foot (fungal infection). |
| What do decomposers (bacteria and fungi) do for the environment? | They break down dead plants and animals, returning nutrients back to the soil. Without them, dead matter would pile up and plants couldn'... |
| What is the difference between transparent, translucent and opaque? | Transparent: light passes through clearly (clear glass). Translucent: some light passes through, blurry (frosted glass). Opaque: no light... |
| What does it mean when a material DISSOLVES in water? | The material breaks into tiny particles that spread evenly throughout the water. The material is still there — it hasn't disappeared. You... |
| Give 3 examples of conductors and 3 insulators of electricity. | Conductors: copper, iron, steel (all metals). Insulators: rubber, plastic, wood, glass, ceramic. |
| Why does wood float but iron sink in water? | Wood is LESS DENSE than water, so it floats. Iron is MORE DENSE than water, so it sinks. Density is how heavy something is for its size/v... |
| What are the 3 types of materials based on how light passes through them? | 1. Transparent (light passes through clearly) 2. Translucent (light partially passes, blurry) 3. Opaque (no light passes through, block... |
| What is the difference between a light SOURCE and a reflected object? | A light source PRODUCES its own light (sun, torch, fire, light bulb). A reflected object only REFLECTS light from a source (moon, mirror,... |
| Why do shadows form? | Light travels in straight lines. Opaque objects block light. The area behind the object that light cannot reach is the shadow. |
| What is REFLECTION of light? | Reflection is when light bounces off a surface. Smooth, shiny surfaces (mirrors) reflect light well. Rough surfaces scatter light in many... |
| What happens to materials when they are heated? When cooled? | Heated → EXPAND (get bigger, particles move faster and spread apart). Cooled → CONTRACT (get smaller, particles slow down and move closer... |
| In which direction does heat always flow? | Heat ALWAYS flows from HOT to COLD. It continues to flow until both objects are at the same temperature (thermal equilibrium). |
| What is the MELTING POINT of water? The BOILING POINT? | Melting point = 0°C (ice melts to water). Boiling point = 100°C (water boils to steam/water vapour). These are fixed temperatures for wat... |
| Name 3 good conductors and 3 poor conductors (insulators) of heat. | Good conductors: metals (iron, copper, aluminium). Poor conductors/insulators: wood, plastic, rubber, cloth, air. |
| Name 4 magnetic materials. | Iron, steel, nickel, cobalt. Remember: NOT all metals are magnetic! Copper, gold, silver and aluminium are NOT magnetic. |
| What is the rule for magnetic poles? | LIKE poles REPEL (N-N or S-S push apart). UNLIKE poles ATTRACT (N-S pull together). 'Like repels, unlike attracts!' |
| Where is the magnetic force STRONGEST in a bar magnet? | At the POLES (the two ends — North pole and South pole). The centre of the magnet has the weakest force. |
| Can magnetic force act through non-magnetic materials? Give 3 examples. | YES! Magnetic force can act through paper, plastic, glass, water, wood and even your hand — without touching! |
| What are the 4 main parts of a plant and their functions? | ROOT: anchor + absorb. STEM: transport + support. LEAF: photosynthesis. FLOWER: reproduction. |
| What are STOMATA and where are they found? | Tiny pores mainly on the underside of leaves. Allow CO₂ IN and O₂ + water vapour OUT (transpiration). |
| What are XYLEM and PHLOEM? | XYLEM: carries water/minerals UP from roots to leaves. PHLOEM: carries glucose DOWN from leaves to rest of plant. |
| What do ROOT HAIR CELLS do? | Tiny extensions that greatly increase root surface area for absorbing water and dissolved minerals from soil. |
| What is the correct order of the digestive system? | Mouth → Oesophagus → Stomach → Small intestine → Large intestine → Rectum → Anus |
| Where does most nutrient absorption happen? How is it adapted? | SMALL INTESTINE. Millions of tiny VILLI increase surface area enormously for absorbing nutrients into the blood. |
| What does the LIVER produce and what does it do? | BILE (stored in gall bladder). Emulsifies (breaks up) large fat droplets into tiny ones so enzymes can digest them. |
| Mechanical vs chemical digestion — what is the difference? | MECHANICAL: physical breakdown — chewing, churning. CHEMICAL: enzymes break bonds in food molecules into small absorbable units. |
| Name the male and female parts of a flower. | MALE: Stamen = Anther (makes pollen) + Filament. FEMALE: Pistil = Stigma (receives pollen) + Style + Ovary (has ovules). |
| Pollination vs fertilisation — what is the difference? | POLLINATION: pollen from anther to stigma. FERTILISATION: pollen nucleus travels to ovule and joins egg cell → seed. |
| 4 methods of seed dispersal with one example each. | WIND: dandelion. WATER: coconut. ANIMAL (eaten): mango. EXPLOSIVE: balsam pod bursts open. |
| What happens to ovary and ovule after fertilisation? | OVARY → FRUIT. OVULE(S) → SEED(S). Fruit protects seeds and aids dispersal. |
| 3 states of matter and their key properties. | SOLID: fixed shape + volume. LIQUID: no fixed shape, fixed volume. GAS: no fixed shape, no fixed volume. |
| Name all 6 changes of state. | Melting, Freezing, Evaporation, Condensation, Boiling, Sublimation |
| Evaporation vs boiling — differences. | EVAPORATION: surface only, any temperature, slow. BOILING: throughout liquid, only at 100°C for water, rapid bubbles. |
| What happens to particles when heated? | GAIN ENERGY → MOVE FASTER → SPREAD APART → material EXPANDS. Reverse when cooled → CONTRACTS. |
| What is needed for a complete circuit? | Battery + wires + component (bulb/motor) + COMPLETE PATH with no gaps. Closed switch allows current to flow. |
| 4 conductors and 4 insulators of electricity. | CONDUCTORS: copper, iron, steel, aluminium. INSULATORS: rubber, plastic, glass, wood, ceramic. |
| Series vs parallel: what happens when one bulb is removed? | SERIES: all bulbs go out (one path broken). PARALLEL: other bulbs stay on (other paths still complete). |
| Why are electrical wires copper coated in plastic? | COPPER = conductor (electricity flows). PLASTIC = insulator (prevents electric shocks and short circuits). |
| 3 categories of materials based on light. | TRANSPARENT: clear (glass, water). TRANSLUCENT: blurry (frosted glass). OPAQUE: no light passes (wood, metal). |
| Luminous vs non-luminous objects. | LUMINOUS: makes own light (Sun, torch, candle). NON-LUMINOUS: only reflects light (Moon, mirror, book). |
| Why do shadows form? | 1. Light travels in STRAIGHT LINES. 2. OPAQUE object blocks light. Area behind object that light cannot reach = shadow. |
| What is reflection of light? | Light bouncing off a surface. Smooth shiny surfaces reflect well. Angle of reflection = angle light hits surface. |
| Name the 4 magnetic materials. | Iron, steel, nickel, cobalt. NOT all metals — copper, gold, silver, aluminium are NOT magnetic! |
| Rule for magnetic poles. | LIKE poles REPEL (N-N, S-S). UNLIKE poles ATTRACT (N-S). You can never isolate a single pole. |
| Can magnetic force act without touching? Through what? | YES — non-contact force. Acts through paper, plastic, glass, water, wood and your hand. |
| What happens if you cut a magnet in half? | Each half becomes a COMPLETE magnet with its own N and S poles. No single-pole magnet is possible. |
| What is ASEXUAL reproduction? | Reproduction using ONE parent — offspring are genetically identical (clones) to parent. Examples: runners, bulbs, cuttings |
| What is SEXUAL reproduction? | Involves TWO parents — fusion of male and female sex cells produces genetically unique offspring |
| What is the difference between POLLINATION and FERTILISATION? | Pollination = pollen transferred to stigma. Fertilisation = pollen nucleus fuses with egg cell in ovule |
| Name FOUR methods of asexual reproduction in plants. | 1. Runners (strawberry) 2. Bulbs (onion, garlic) 3. Cuttings (cactus) 4. Tubers (potato) |
| What are the advantages of ASEXUAL reproduction? | Fast, only one parent needed, offspring survive well in stable environments, efficient (no pollination needed) |
| List the path of air from the nose to the alveoli. | Nose/Mouth → Trachea → Bronchi → Bronchioles → Alveoli |
| What gas exchange happens at the ALVEOLI? | Oxygen passes INTO blood; Carbon dioxide passes OUT of blood into alveoli to be exhaled |
| What is the role of the DIAPHRAGM? | Contracts to increase chest volume (inhale) — relaxes to decrease chest volume (exhale) |
| Name THREE adaptations of alveoli for efficient gas exchange. | 1. Thin walls (one cell layer) 2. Rich blood supply 3. Enormous numbers (480 million) = huge surface area |
| What is the difference between BREATHING and RESPIRATION? | Breathing = physical movement of air in/out. Respiration = chemical reaction in cells releasing energy from glucose + O₂ |
| Name the FOUR components of blood and one function of each. | Red blood cells (carry O₂), White blood cells (fight infection), Platelets (clot blood), Plasma (carries nutrients, hormones, CO₂) |
| Why do red blood cells have NO nucleus? | More space for haemoglobin — the oxygen-carrying protein. They are also disc-shaped to maximise surface area |
| What is PULMONARY circulation? | Blood circulation between the heart and lungs — to collect oxygen and release carbon dioxide |
| What is the difference between ARTERIES and VEINS? | Arteries = carry blood AWAY from heart (thick walls, high pressure). Veins = blood TOWARDS heart (thin walls, valves to prevent backflow) |
| How do WHITE BLOOD CELLS defend the body? (2 ways) | 1. Phagocytosis — engulf and destroy bacteria 2. Antibody production — target specific pathogens |
| What DRIVES the water cycle? | The Sun provides heat energy for evaporation and transpiration. Gravity pulls precipitation back down |
| What is EVAPORATION? | Liquid water absorbs heat energy and turns into water vapour — occurs from oceans, lakes, rivers, puddles |
| What is CONDENSATION in the water cycle? | Water vapour cools at high altitude → forms tiny water droplets → creates clouds |
| What is PRECIPITATION? | Water falling from clouds — as rain, snow, hail, or sleet — returning water to Earth\ |
| What is TRANSPIRATION? | Plants release water vapour through stomata in leaves — contributes significant moisture to atmosphere |
| Name THREE desert adaptations of a cactus. | 1. Thick stem stores water 2. Waxy coating reduces evaporation 3. Spines instead of leaves (less surface area = less water loss) |
| Name THREE arctic adaptations of a polar bear. | 1. Thick white fur (camouflage + insulation) 2. Thick layer of blubber (insulation) 3. Large padded feet (grip on ice) |
| How are fish adapted for aquatic life? (3 features) | 1. Streamlined body (low drag) 2. Gills (extract dissolved O₂ from water) 3. Fins (propulsion and steering) 4. Scales (protection) |
| Name TWO structural adaptations of eagles for hunting. | 1. Sharp curved talons (grip and kill prey) 2. Hooked beak (tear flesh) 3. Keen eyesight (spot prey from great heights) |
| How are deep-sea fish adapted for life in total darkness? | Large eyes (maximise light collection), bioluminescence (attract prey/mates), sensitive lateral line (detect water movements) |
| What do ARROWS in a food chain represent? | Direction of ENERGY TRANSFER — from organism being eaten → to organism eating it |
| What is a PRODUCER? Give an example. | Organism that makes its own food by photosynthesis. Examples: grass, seaweed, algae, trees, phytoplankton |
| What is a PRIMARY CONSUMER? | Animal that eats producers (plants) directly — a herbivore. Examples: caterpillar, rabbit, grasshopper, cow |
| What is a SECONDARY CONSUMER? | Animal that eats primary consumers. Examples: fox (eats rabbit), frog (eats insects) |
| What is an APEX PREDATOR? | Top predator with no natural enemies. Examples: lion, great white shark, orca, eagle |
ScienceStar's printable summary sheets are designed specifically for Singapore Primary Science students from P3 to PSLE. Each sheet is a single A4 page covering one topic — with key definitions, concept explanations, a diagram or table, and 3 to 5 exam-style practice questions with model answers. They are designed to be printed in black and white or colour and used for last-minute revision, classroom reference, or weekend study sessions.
Unlike full textbooks or thick revision guides, these sheets are deliberately concise. Each one can be read and reviewed in 10 to 15 minutes. The goal is to give students the most important information for each topic in the most efficient format possible — so they can revise more topics in less time.
Printable sheets are available for all major PSLE Science topics including Forces and Simple Machines, Electrical Systems, Photosynthesis, Food Chains and Food Webs, Matter and Materials, the Water Cycle, Plant Reproduction, Animal Adaptations, the Digestive System, the Respiratory System, Magnets, Light and Shadows, Living and Non-Living Things, and the Environment. New sheets are added regularly as the site grows.
For best results, use the printable sheets as part of a structured revision routine rather than reading them passively. A recommended approach is to read the sheet once, then cover the definitions and try to write them from memory, then check. Next, attempt the practice questions without looking at the model answers. Finally, compare your answers to the model answers and note any missing keywords. This active retrieval approach is significantly more effective for long-term memory retention than simply reading the sheet multiple times.
Parents often find these sheets useful for testing their child at home without needing a science background themselves. The model answers on each sheet show exactly what the examiner expects — making it easy to check if your child's answer is complete and contains the right keywords, even if you are not a science teacher.
💡 Tip for PSLE students: In the 2 weeks before your PSLE, print one sheet per day and do a timed 10-minute review each morning before school. By exam day, you will have reviewed all 15 major topics at least once and the key definitions will feel familiar and automatic.