The secret to IB Biology exam success

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We have worked with the TutorsPlus IB Biology Teachers and Examiners to give you their best advice so that you can get the best marks and Biology IB exam success

Looking through all the advice this is the one piece that makes the biggest difference on exam day. “Be 100% sure you understand what the exam question is asking.”

Our IB Biology examiners say that many students miss what the exam question is asking them to do, and this results in students’ missing out on key points.

Often students clearly know IB Biology exam topic, but the examiner cannot award full marks, because of the way they have answered the question.

The key is to remember what IB teachers call “command terms.”

2 IB students with microscope

So, what do you need to do to make sure you don’t miss out on important marks?

As you move through the course, and as you do past exam questions, try to highlight and get into the habit of taking specific note of each command term. So that you get to a point where you know them and their specific meaning by heart.

Without a sound grasp of the precise meaning, you will find you are often not answering the question accurately and miss out on your chance of IB exam success.


This is a straightforward question, usually for one mark only.  You need to learn by heart the definitions word for word as they always come up. You will find these definitions in the course outline under the “Understandings” for each topic.


Here you need to create a pencil image of one of the drawings you need to be able to reproduce (a list is available). Always label your drawings unless told not to. These are under “Skills” in each topic

The scale and proportion need to be correct, and there should be an arrow pointing precisely and unambiguously at each part. Plus, it must be correctly labeled, of course.


As simple as it seems.  This means adding labels to a diagram.


This means that the examiner wants a list of names or very brief answers. There is no explanation needed and it doesn’t require full sentences.


Find the value for a quantity.


Here, the examiner wants a brief answer. No need for an explanation or calculation. So, any extra information included here will gain no marks, and be a waste of precious time. Often these are one-word answers.


Put brief notes on a graph or diagram. The difference with label is that this demands “notes” so is not just one word. In Biology, this often means a description of the function of the named part. e.g., Ribosome: site of protein synthesis (translation of mRNA).


Give a numerical answer and don’t forget to show your workings (unless otherwise stated). Units are almost always required for completeness.


Give a detailed summary or account of something (this is probably a biological process).

Though there is a warning here!

Our examiners often remark that there is a temptation for students to give long answers.  However, first look at the marks on offer and make sure your response addresses each mark.

Graphs advice – Be very careful to check the marks awarded for each part of a data analysis question. Read the axes carefully to be aware of the variable under discussion and the units, as well as the increment on any axes so that you can read values carefully. Often students under pressure in exams assume increments of 1 on any scale so always best to establish what any gridlines represent. Are they increments of 1, 2, 5, 0.2 etc.?


With this command term, you are being asked to compare (usually) two things. So, you will want to be sure that your language is focusing on comparing AND contrasting. Then, make sure these differences are clear to the examiner.


This command term requires you to find an approximate value that is not stated or known. Again, it is important to show your workings.


Select the answer from the number of possibilities given.


This requires a summary and is closest to the command term describe but requires a shorter answer.  Again, it is important to look at the number of potential marks. Then you can ensure you are providing the correct length of answer to capture them all.

A pitfall is providing too much detail that isn’t needed and wasting time.

A graph may be used in your answer and clearly sketching the correct curve on a graph with appropriately labeled axes to show patterns or trends can gain valuable marks whilst taking less time than writing.


Used in data questions in papers 2 and 3, this requires the student to interpret the data to arrive at a valid conclusion.

Often you need to analyse multiple data sources.

You may be asked to analyse concepts themselves and these may well come from previous questions you have answered in the paper.


Questions using comment are asking for your opinion or judgment. It could be about a statement you are given or a calculation you have made.


This is like “distinguish” where the examiner is looking for you to compare (usually) two things. The Key is to use your language to focus on comparing AND contrasting throughout your answer. Typically, questions seek 2 similarities and 2 differences from students.


This requires you to represent something in the form of a graph.


This is a term that typically asks students to state their conclusion on information or data extracted from graphical information (or other data representation) on the exam paper.


Produce a plan, simulation, or model. This is generally linked to a concept replicating a form of practical investigation


Only one answer is possible, and you need to solve to find it.


This is usually a higher mark question that requires a more developed answer. IB Biology examiners want an account of a number of arguments for and against the relative importance of various factors or comparisons of alternative hypotheses. Often you will need to support claims by specific reference to data in the question.


This command term is similar to discuss but implies a weighing of potentially conflicting evidence. Here you need to present the pros and cons, the implications and limitations. However, at the same time, more emphasis is placed on your final opinion or conclusion.


This one can often be misunderstood by students, who can launch into a long and vague description. However, the requirement for these questions is quite specific. You must make an observation and explain the rationale behind it. This must include the causes, reasons, or mechanisms and as such must be sufficiently detailed. These questions are often associated with high numbers of marks and require one clear supporting idea per mark.


Give the result you expect to happen.


Represent by means of a graph showing a line and labeled but unscaled axes, but with important features (for example, intercept) clearly indicated.


Provide a hypothesis, theory, or other potential answers.

Whether you are taking HL or SL IB Biology these tips will help you approach your IB mocks and final IB Biology exams with confidence and give you an even stronger chance of IB Biology exam success.

For help in your multiple-choice Paper 1, or to book a lesson with us on any IB Biology topic, HERE.

To see more of our IB Biology teachers, check out our IB Biology page HERE.

You can find more details on the external assessment of the Biology IB Diploma here.

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