Preparing for your IGCSE Science exam? Understanding and mastering IGCSE Science command words is crucial for answering exam questions accurately.
Cracking the IGCSE Biology, Chemistry, Physics, Combined Science or Coordinated Science exams requires more than just memorizing facts. To secure top grades in Biology, Chemistry, Physics and Science students must understand how to answer questions based on specific command words. These words, used by Cambridge International, indicate exactly what the examiner expects. Misinterpreting them can mean the difference between a grade A and an A*.
In this guide, we break down the most important command words in IGCSE Sciences and how to approach them effectively in your exam.
Understanding Command Words in IGCSE Science
1. Define
What it means: State the exact meaning of a term as given in the syllabus without additional explanation.
Example: Define a gene.
How to answer: A gene is a length of DNA that codes for a protein.
2. Describe
What it means: State the points of a topic / give characteristics and main features
Example (Chemistry): Describe metallic bonding
How to answer: Include relevant details, such the electrostatic attraction between the positive ions in a giant metallic lattice and a ‘sea’ of delocalised electrons.
3. Explain
What it means: Set out purposes or reasons / make the relationships between things evident / provide why and/or how and support with relevant evidence
Example (Physics): Explain why resistance increases with temperature in a metallic conductor.
How to answer: Use scientific reasoning and key concepts.
**Example (Chemistry): How alloys can
be harder and stronger than the pure metals.
How to answer: because the different sized atoms in alloys mean the layers can no longer slide over each other
4. Compare
What it means: Identify similarities and differences.
Example (Biology): Compare nervous and hormonal control
How to answer: Use comparative language such as ‘whereas,’ ‘similarly,’ or ‘on the other hand.’ in terms of speed of action and duration of effect
5. State
What it means: Provide a simple, concise answer.
Example: State the SI unit of force.
How to answer: One-word or short-phrase response (Newton).
6. Calculate
What it means: Use mathematical formulas and show working.
Example (Physics): Calculate the acceleration of an object given a force of 10N and a mass of 2kg.
How to answer: Apply F = ma, show steps, and include correct units.
7. Suggest
What it means: Apply knowledge and understanding to situations where there are a range of valid responses in order to make proposals / put forward considerations
Example (Biology): Suggest why an enzyme might become denatured at high temperatures.
How to answer: Give logical reasoning with scientific terms.
8. Outline
What it means: set out main points
Example (Chemistry): Outline the role of bile
How to answer: Provide a step-by-step summary without unnecessary detail, emulsifying fats and oils to increase the surface area for chemical digestion
9. Evaluate
What it means: Judge or calculate the quality, importance, amount, or value of something
How to Answer IGCSE Science Exam Questions Effectively
- Read the question carefully. Identify the command word.
- Highlight keywords. Pay attention to what the question is truly asking.
- Structure your answer. If the command word is ‘explain,’ include cause-and-effect reasoning.
- Use scientific terms accurately.
Top Tips for IGCSE Science Exam Success
- Practice past papers: Familiarize yourself with the format of exam questions.
- Create summary notes: Write concise revision notes focusing on command words.
- Use diagrams where applicable: Especially for ‘describe’ and ‘explain’ questions.
- Time management: Allocate time based on marks per question.
By mastering these command words, you can ensure you’re answering questions exactly as the examiner expects, boosting your IGCSE Science scores. Need extra support? Our IGCSE Crash Course provides expert tutoring to help you ace your Biology, Chemistry, and Physics exams. Book your spot today!