IB Biology exams are not just about what you know. They are about how you respond to the question. Many students lose marks not because they do not understand the content, but because they misunderstand the IB Biology command terms used in the question.
Command terms are the instruction words in exam questions. They tell you exactly what the examiner expects you to do. For example, a question may ask you to describe, explain, or evaluate a concept, and each of these requires a different type of response.
If you have ever written a detailed answer and still received a lower mark than expected, this is often the reason.
In this guide, we break down 7 essential IB Biology command terms and show you how to approach each one effectively, so you can apply your knowledge more accurately under exam conditions.
1. Describe
Among the most common IB Biology command terms, “describe” requires students to give a clear and detailed account of what is observed.
What students often do wrong:
They start explaining why something happens instead of focusing on what can be observed.
Example question:
Describe the structure of DNA
Strong answer approach:
- Mention key features such as the double helix, two strands, and base pairing
- Focus on observable characteristics, rather than explanations
2. Explain
Another key command term in IB Biology is “explain,” which requires students to give reasons and show understanding of how or why something happens.
What students often do wrong:
They describe the process without explaining the underlying cause
Example question:
Explain how temperature affects enzyme activity
Strong answer approach:
- State what happens
- Then explain why, using relevant concepts such as kinetic energy, collisions, or denaturation
Tip: Higher marks are rewarded when clear links are made between cause and effect
3. Compare
What students often do wrong:
They only give similarities, which means they cannot access full marks.
Example question:
Compare mitosis and meiosis.
Strong answer approach:
Include at least one similarity and one difference
Present answers clearly, for example using paired points
4. Contrast
Example question:
Contrast DNA and RNA.
Strong answer approach:
Structure differences such as double versus single strand
Functional differences
Tip: Some IB Biology command terms are often combined in exam questions. One of the most common examples is “compare and contrast…”
5. Evaluate
When IB Biology command terms ask you to “evaluate,” you need to consider both strengths and limitations.
What students often do wrong:
They only give advantages without considering drawbacks
Example question:
Evaluate the use of animal testing in scientific research
Strong answer approach:
- Include at least one advantage and one disadvantage
- Focus on balanced judgement rather than just one side
- A formal conclusion is not required to gain full marks
Tip: Higher marks are awarded when responses show clear balance and use relevant biological knowledge to support each point.
6. Suggest
“Suggest” is one of the more open-ended IB Biology command terms, requiring you to propose a logical idea based on your knowledge.
Important:
There is often no single correct answer, but responses must be logical and grounded in biological knowledge
Example question:
Suggest why a plant grows faster under blue light
Strong answer approach:
- Link to known concepts such as photosynthesis or light absorption
7. Discuss
“Discuss” is one of the more complex IB Biology command terms and is commonly used in longer, higher-mark questions. It requires you to present a balanced argument using evidence. Strong responses also demonstrate the ability to weigh evidence, not just present it.
What students often do wrong:
They only present one side of the argument or list facts without evaluating the quality of the evidence
Example question:
Discuss the evidence for the theory of evolution
Strong answer approach:
- Include at least one supporting point, such as fossil records or genetic evidence
- Identify at least one limitation or gap in the evidence
- Show some level of balance rather than focusing on only one perspective
How to use IB Biology Command Terms Effectively
Two students can have the same level of knowledge but achieve different scores. This is often due to how effectively they respond to IB Biology command terms.
A strong understanding of command terms helps you:
- Avoid irrelevant answers
- Structure your responses clearly
- Maximise marks using the same knowledge
To apply this in the exam, start by underlining the command term in each question. Recognising IB Biology command terms early helps you plan your answer more effectively.
Before writing your response, ask yourself:
- Am I being asked to describe or explain?
- Am I comparing or contrasting?
- Do I need to make a judgement?
Mastering IB Biology command terms is a simple but high impact habit that can significantly improve your performance.
IB Biology Exam Support at ITG
In IB Biology, marks are not only awarded for what you know, but for how accurately you respond to the command term. At International Tutor Group, we support students in going beyond content knowledge by developing strong exam techniques. This includes interpreting command terms accurately, structuring answers effectively, and avoiding common mistakes that cost marks.
Our lessons are tailored to each student, ensuring they develop both subject knowledge and the skills needed to apply it confidently under exam conditions. This combination is often what makes the biggest difference in improving grades.
Whether a student is aiming to pass or achieve a 7, having the right exam strategy can have a significant impact on their results.
