IB Biology Internal Assessment Solved: A Guide to Acing Your Biology IA (2025 Syllabus)

What is a Biology IA?

The Biology Internal Assessment (IA) is a take home report on a research question of your choice. It is worth 20% of your final grade and thus it is important to perform well in it. The Biology IA can be daunting. It has a 3000-word limit, which might seem like a lot to do, but towards the end of the IA you’ll be wishing you had more words to work with. This blog is aimed to help you write the IA and to answer any questions you may have.

Choosing a Research Question

The most difficult part of the IA is choosing a research question. There are thousands of topics out there all of which are interesting. However unfortunately when conducting research, you are restricted to scope and the equipment which is available. Well how can you find a topic?

In order to find a topic, I would first choose a syllabus point which sounds appealing to you. Once you have found a syllabus point start googling experiments which have been conducted on that point. They do not have to be identical. DO NOT choose the first experiment you find. I would recommend collecting multiple experiments and read through all of them noting down how it was conducted and whether they had any unanswered questions.

These unanswered questions should be used as motivation when creating a research question. From here you can conduct further research to determine whether it is in the scope or not. If it is then you now have a research question to base your IA off. If it is outside the scope attempt to simplify the question or narrow the focus to that of which you can work with.

Conducting Research

Now that you have your research question it is time to gain background knowledge. Background knowledge is crucial as not only does it enhance your understanding of the topic, but it will be used in your IA to help the reader understand the topic.

When conducting research, the biggest mistake people make is using refutable sources. I would recommend using only published research articles as they have the most evidence to support their claims. This will enhance the reliability of your IA as information you are using is backed up by multiple sources. HOWEVER, it is crucial to ensure that you reference in APA format. We will explore referencing later in the article.

The research you gather should be used in your IA to explain to the reader the reasoning behind your question and to explain any concepts which may be confusing or abstract.

Undergoing the Experiment

Once you have conducted your research you are ready to create your method. The method you create to conduct the experiment is the same method you will place in your report. So, I would recommend that your method is detailed and concise. To ensure this, pretend that you are writing a method to someone who has never conducted an experiment before. This not only makes the method easy to follow for others, but for yourself too ensuring that the experiment is conducted smoothly.

It is important that you conduct multiple trials. This will be explored in your evaluation as the more trials you conduct the more accurate and reliable your results become. However, when conducting multiple trials, try to conduct them during the same time period as it reduces the number of controlled variables.

Also, keep in mind that there is a possibility that the experiment may not work or that it may have varying results. If that occurs, do not stress, it is completely normal and will give you more to discuss later in the evaluation.

Writing the Report

Now for the fun part. Writing the report. When writing the report there are some sections which are more difficult than others. Below I will explore the sections most students find difficult to complete in a coherent manner.

Background Information

This section involves the most external information. Here you will collate all the information you have gathered on your research question and explore it. One key mistake student make is they do not systematically explore the information. I would recommend inserting subheadings for the various concepts you will explore, ie: 1.1: Photosynthesis, 1.2: electromagnetic spectrum, 1.3 Mentha spicata L, spearmint. Through using subheadings, it becomes easier for the marker to follow the report.

Paraphrase, Paraphrase & Paraphrase. One common mistake students make is that they “dump” information into their report and reference it. AVOID THIS. Instead, I would recommend paraphrasing information, explaining it and its relevance to the report.

Materials, Risks, Environment and Variables

Listing materials is easy and is probably the easiest part of the IA. However, many students to forget to insert the uncertainties for measuring instruments. This is very important as uncertainties must be explored in the weaknesses section for the IA.

Risk assessment should be included in the IA. It ensures that potential hazards which may arise during the experiment have been identified and precautions installed. It also ensures that if someone were to repeat the experiment, they are also aware of the dangers.

The experiments should all be ethical. Hence environmental considerations should be addressed to show that ethical considerations were taken into account and methods of were implemented to ensure the environment was not harmed.

All variables should be discussed in the report. This includes independent, dependent and controlled variables. When listing the variables, it should be discussed how they were controlled and why they should be controlled This increased personal engagement as it shows the marker that there was constant reflection being conducted.

Qualitative and Quantitative

When discussing results both quantitative and qualitative results should be discussed. When discussing quantitative results, I would recommend using tables and graphs. It allows for clear and concise representation of information and allows for easier comparisons and discussions.

Averages and standard deviation for the graphs and tables should be explored as they allow for more accurate and justified conclusions to be drawn. Other tests such as t test, Tukey’s statistical difference test or chi squared test can be used to enhance the IA and discussion of results.

Qualitative analysis consists of differences which can be visually identified. Here you discuss differences in visual representation before the experiment was conducted to after the experiment.

Conclusion and Evaluation

This section comes towards the end of the IA. Here is where we summarise our findings from both the quantitative and qualitative sections. The best way to think about what to include in your conclusion is this: If someone were to read only this section would they understand what the entire IA explored.

The evaluation can seem daunting as you may have a lot to write about. The three most important things to include in your evaluation should be: Accuracy, Validity and Reliability. These should be explored as they establish whether your findings should be taken seriously or whether they should not. To further enhance your evaluation, using journal articles which explored similar concepts to your IA can be referred to and compared.

Weaknesses

As part of the new syllabus, commenting on Strengths of the investigation is no longer required. Instead, we now focus on weaknesses: In this section I would recommend listing 4-5 weaknesses, commenting on how they affected the report or experiment. You should then explore how you can improve this if you were to conduct the experiment again.

Reference list (APA format)

Ensure all in text references are listed at the end of the IA in APA format and alphabetical order. If this is difficult, I would recommend using the reference tab on a word document. Once you insert the information it converts it to APA format and will list it alphabetically for you.

Remember that the examiners are focusing on the detail of your report and your reflection. If you find that there was an error in the experiment, DISCUSS IT.

And that's it! From here, you should be well-equipped to begin your Biology Internal Assessment. But if you're still scratching your head, wondering if there are any examples you can follow to achieve a high mark, make sure to check out our top-scoring 23/24 IB Biology IA Example.

Or even better, click below to work with one of our expert IB Biology tutors who can guide you personally through the complete process of achieving top marks in your own Biology IA!

Contact Us