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Decoding the IB Biology Command Terms: How to Speak "IB-ese"

If you have ever walked out of an IB Biology exam feeling like you nailed a question, only to receive a 2 out of 6 on the markscheme, you’ve likely fallen victim to a Command Term error.

In the world of the International Baccalaureate, the verb at the start of the question, the "Command Term", is more than just an instruction; it is a code that dictates the depth, structure, and length of your response. To reach a Grade 7, you don't just need to know biology; you need to speak the language of the examiners and know what is expected.

1. The Hierarchy of Command Terms

The IBO categorizes command terms into three "Assessment Objectives" (AOs). Understanding which level you are playing at is the first step to a perfect score.

• AO1: Knowledge and Understanding (The Basics) — Define: Give the precise meaning of a word or concept. State: Give a specific name, value, or brief answer without an explanation. List: Provide a series of items with no elaboration.
• AO2: Application and Analysis (The Middle Ground) — Annotate: Add brief notes to a diagram or graph. Calculate: Provide a numerical answer showing the relevant stages of working. Distinguish: Make clear the differences between two or more items.
• AO3: Synthesis and Evaluation (The "Big Mark" Questions) — Discuss: Offer a balanced review that includes a range of arguments or hypotheses. Explain: Give a detailed account including reasons or causes. Evaluate: Make an appraisal by weighing up the strengths and limitations.

2. "Describe" vs. "Explain": The Mistake That Costs Points

This is the most common trap in IB Biology.

Describe asks you to state what is happening. If you see a graph of enzyme activity, you describe the peaks and the drops.

Explain asks you to state why it is happening. You must mention collision theory, denaturation, or active sites.

Pro-Tip: If the question says "Explain" and you haven't used the word "because" or "therefore," you probably haven't answered the question fully.

3. The Power of "Compare and Contrast"

When the IB asks you to Compare and Contrast, they are looking for both similarities and differences. A common mistake is only listing the differences. To maximize points, use a table format in your rough notes to ensure you have a 1:1 match for every point of comparison.

For example, if comparing Prokaryotic and Eukaryotic cells, don't just say "Eukaryotes have a nucleus." You must balance it: "Eukaryotes have a membrane-bound nucleus, whereas Prokaryotes have a nucleoid region with naked DNA."

4. How ipassed.gg Helps You Master Command Terms

Our question bank doesn't just give you the right answer; it helps you recognize the pattern of the command terms.

Active Recall with Blur: When you use our "Option Blur" feature on an Explain question, you are forced to mentally construct the "why" before seeing the "what." This replicates the pressure of Paper 2 Section B.

Conclusion: Practice Makes Permanent

Mastering command terms is a skill, not a talent. It requires repetitive exposure to high-quality questions that mirror the actual IB style. By shifting your focus from "what is the answer" to "how should I phrase the answer," you unlock the door to the highest grade boundaries.