GCE O/L Science study guide
GCE O/L Science · Work through your exam, one topic at a time.
GCE Ordinary Level Science is a school-leaving science qualification taken in several countries and awarded by different examination boards, so the exact syllabus, paper structure and grading scale depend on which board you sit. It is designed for students around the mid-secondary stage and typically serves as a prerequisite for Advanced Level science study, technical training, or entry-level employment where basic scientific literacy is expected. The GCE O/L Science study guide has 12 sections and about 3,719 words.
01Cells, Transport and Biological Molecules
All living things are built from cells. Plant and animal cells share a cell membrane, cytoplasm, nucleus, mitochondria and ribosomes.
345 words, about 2 min02Nutrition, Respiration and Gas Exchange
Photosynthesis uses light energy trapped by chlorophyll to convert carbon dioxide and water into glucose and oxygen: 6CO2 + 6H2O → C6H12O6 + 6O2. Light intensity, carbon dioxide concentration and temperature can limit the rate.
329 words, about 2 min03Transport Systems, Excretion and Homeostasis
Humans have double circulation: the right side of the heart pumps blood to the lungs and the left side pumps it around the body. Arteries carry blood away from the heart and have thick elastic walls; veins carry blood back and contain valves; capillaries are one cell thick for exchange.
334 words, about 2 min04Reproduction, Inheritance and Variation
A flower has sepals, petals, stamens (anther and filament) and carpels (stigma, style and ovary). Pollination is the transfer of pollen from anther to stigma; fertilisation is the fusion of a male gamete with an egg inside the ovule.
312 words, about 2 min05Ecology, Environment and Human Influence
A habitat is where an organism lives; a population is all organisms of one species in an area; a community is all populations together; an ecosystem includes the community and its physical environment. Food chains begin with a producer, and arrows show the direction of energy flow.
293 words, about 1 min06Atomic Structure, Bonding and the Periodic Table
An atom has protons and neutrons in the nucleus and electrons in shells. Atomic number = number of protons; mass number = protons + neutrons.
316 words, about 2 min07Chemical Reactions, Stoichiometry and the Mole
A balanced symbol equation has the same number of each type of atom on both sides. The mole is the amount containing 6.02 × 10^23 particles; moles = mass ÷ molar mass (Mr).
292 words, about 1 min08Acids, Bases, Salts and Qualitative Analysis
An acid releases hydrogen ions (H+) in water; a base neutralises an acid; an alkali is a soluble base that releases hydroxide ions (OH−). The pH scale runs from 0 to 14: below 7 is acidic, 7 neutral and above 7 alkaline.
310 words, about 2 min09Metals, Non-metals and Organic Chemistry
The reactivity series ranks metals from potassium (most reactive) to gold (least). Metals above carbon are extracted by electrolysis; less reactive metals such as iron are reduced with carbon.
275 words, about 1 min10Mechanics, Forces and Motion
Speed = distance ÷ time. Velocity is speed in a given direction, and acceleration = change in velocity ÷ time.
301 words, about 2 min11Energy, Waves, Light and Sound
Energy is conserved: it is transferred between stores but not created or destroyed. Work done = force × distance, and power = energy transferred ÷ time.
281 words, about 1 min12Electricity, Magnetism and Thermal Physics
Current is the rate of flow of charge. In series, current is the same everywhere and voltage splits; in parallel, voltage is the same across branches and current splits.
331 words, about 2 min