Exams in Combined Science can feel like a puzzle with pieces scattered everywhere. One moment, you’re confident in biology, the next, chemistry formulas start spinning around, and physics concepts seem completely alien. It’s easy to get lost, but once the core ideas are clear, everything begins to click.
In this article, we’ve gathered the ten essential concepts that tie everything together. With them in your corner, exam questions will feel much more manageable.
Why core concepts matter in IGCSE Combined Science
Exam boards focus on understanding, not just remembering. Instead of recalling dry facts, you should link biology, chemistry, and physics to explain the world. But how exactly do examiners look for these connections across assessment papers? Let’s find out below.
How exam questions test understanding across biology, chemistry, and physics
Modern exams use structured questions, graphs, data tables, and diagrams to challenge students’ logic. You might be asked to calculate energy transfers in a biological system or apply physical laws to chemical reactions. These “crossover” questions demonstrate your broad knowledge.
Biology concepts you must know
Biology is essentially the study of how life functions at every level. To succeed, you need to see how tiny structures support entire organisms. The section below outlines the four essential biological pillars that frequently appear on exam papers.
Cells, organisation, and biological systems
Cells make up all living things, so it’s crucial to study how they organize into tissues, organs, and systems. Beyond structure, concentrate on coordination between systems and membrane transport processes such as diffusion, osmosis, and active transport.
Photosynthesis, respiration, and energy transfer
These processes explain how energy enters and moves through living systems. Photosynthesis stores energy in glucose, while respiration releases it for cellular activities. Pay special attention to aerobic and anaerobic respiration, energy losses, and the transfer of energy between trophic levels.
Genetics and inheritance fundamentals
This topic covers how traits pass from parents to offspring through DNA and alleles. You should be comfortable using genetic diagrams and Punnett squares to predict outcomes. It is also important to understand how variation within a species drives natural selection and evolution over time.
Ecology and human impact on the environment
Ecology examines how organisms interact with their environments. It covers ecosystems, food chains, and nutrient cycles, alongside human influences such as pollution, deforestation, and climate change, and their biological consequences.
Chemistry concepts you must know
Chemistry explores how substances interact, change, and make up the world around us. While school lab experiments provide a hands-on start, the exam requires you to visualize these processes at a molecular level. Let’s break down three core areas that form the foundation of most chemistry questions.
Particle model and states of matter
All substances around us take the form of:
- solid,
- liquid,
- or gas.
The particle model explains how these states behave in terms of energy and arrangement. It is vital to understand how particle arrangement affects density, diffusion, and phase changes. These constitute the basis of many exam questions.
Acids, bases, pH, and neutralisation
Acids release hydrogen ions, which determines their position on the pH scale. Conversely, bases produce hydroxide ions that shift the scale toward alkalinity. When these two meet, they undergo neutralisation to form salt and water. It is essential to be familiar with measuring pH, predicting neutralisation products, and recognising real-life examples.
Basic chemical reactions and equations
Equations are the language of chemistry. Begin by understanding the fundamental types of reactions, namely:
- combustion,
- decomposition,
- displacement,
- and redox.
Start with word equations before progressing to balanced symbol equations. Useful advice is to track the number of atoms on each side systematically.
Physics concepts you must know
Physics is all about the rules that govern the universe, from massive forces to tiny particles. Below are four essential topics that you should review thoroughly in the months leading up to your final exam.
Energy forms, transfers, and efficiency
Energy is neither created nor destroyed but can change from one store to another, taking forms like kinetic, potential, thermal, or chemical.
Energy is neither created nor destroyed but can be transferred from one energy store to another, such as kinetic, potential, thermal, or chemical stores. When preparing, consider energy transfers, system efficiency, and calculations involving energy changes.
Forces, motion, and simple graphs
This area links how objects move with the forces acting upon them. You need to master distance-time and velocity-time graphs to describe motion accurately. Don’t forget to practice calculating resultant forces and understanding how friction or gravity affects an object’s acceleration.
Electricity basics and simple circuits
Electricity relies on a solid grasp of current, voltage, and resistance. You should be able to draw and interpret series and parallel circuits, as well as apply Ohm’s law to calculate missing values. Knowing how components like resistors or lamps change the flow is vital for passing practical-based questions.
Waves: light and sound essentials
Waves transfer energy without moving matter itself. You should distinguish between longitudinal and transverse waves while mastering terms like wavelength, period, and wave speed. Focus on properties such as reflection, refraction, frequency, and amplitude for both light and sound.
How to master these 10 concepts efficiently
Understanding the theory is a good start, but the right tools are needed to make it stick. Let’s look at two practical methods to sharpen your skills.
Using diagrams, equations, and key definitions
Visual aids are your best friend in science. Draw labeled diagrams, write out equations, and highlight key terms. In addition, rewriting concepts in your own words can reinforce memory and save hours during revision.
Practising exam questions and applying knowledge
Regular practice is a must. Experience working through past papers with time limits helps improve speed and accuracy. When reviewing mistakes, note weak points and record the correct approach for similar questions.
How TutorsPlus supports IGCSE Combined Science students
Dealing with three sciences at once is challenging, which is why guidance from IGCSE science tutors can be very helpful. TutorsPlus offers high-quality tutoring from skilled teachers and examiners. In face-to-face or online sessions, the tutor provides an individualised approach to teaching that builds both grades and self-assurance. After a brief consultation, we match you with an expert and offer a free trial to ensure the right fit.
Achieve your science success
Grasping these ten foundations turns exam pressure into a clear path for strong results. Stay consistent with active revision, practice a lot, and remember that professional assistance can fill any remaining gaps. With focus and persistence, the exam will become your opportunity to shine!