This topic explores how an organism's genome and its interaction with the environment influence its characteristics, including the mechanisms of inheritance and the process of evolution. It covers the structure of DNA, the principles of genetic crosses, and how natural selection drives biodiversity and adaptation over time.
Electricity is a fundamental topic in GCSE Combined Science, covering the behaviour of electric circuits, the flow of charge, and the transfer of energy. You will explore key concepts such as current, voltage, and resistance, and learn how to analyse series and parallel circuits. Understanding electricity is essential not only for exams but also for everyday life, as it powers homes, devices, and technology.
This topic builds on basic ideas of energy and forces, and introduces mathematical relationships like Ohm's Law (V = IR). You will also study the National Grid, electrical safety, and the cost of electricity. Mastery of electricity is crucial for further study in physics and engineering, and it appears frequently in exam questions, often requiring both calculations and explanations.
In the WJEC specification, electricity is split into two main sections: 'Electric Circuits' and 'Mains Electricity'. You will need to recall circuit symbols, draw and interpret circuit diagrams, and understand the difference between direct current (DC) and alternating current (AC). Practical skills are also assessed, so you should be comfortable setting up circuits and taking measurements.
Key skills and knowledge for this topic
Key points examiners look for in your answers
Expert advice for maximising your marks
Pitfalls to avoid in your exam answers
Common questions students ask about this topic
How questions on this topic are typically asked
Practice questions tailored to this topic