how to write biology ia methodology

Biology IA Checklist

How To Write a Perfect Biology IA

Enter your email to get the guide!

Success! The Guide is on it's way to your inbox now!

80 most common ib biology exam questions.

Enter your email and tell us where to send them!

Great! The Questions are on their way to your inbox!

Pin it on pinterest.

• Find A Tutor
• Geneva Tutors
• Lausanne Tutors
• Zurich Tutors
• Basel Tutors
• Online Tutors
• Maths Tutors
• Chemistry Tutors
• Physics Tutors
• Biology Tutors
• English Tutors
• History Tutors
• Geography Tutors
• Language Tutors
• Special Educational Needs
• Residential Tutors
• Primary School
• School Entrance Exams
• Middle School
• Combined Science
• Maths AA and AI
• IB Internal Assessment
• Environmental Systems & Societies (ESS)
• Sports, Exercise & Health Science
• Computer Science
• Global Politics
• Digital Society
• Business Management
• Visual Arts
• English A/B
• English Oral (IO)
• German Oral (IO)
• French Oral (IO)
• Spanish A/B
• French Ab Initio
• German Ab Initio
• Spanish Ab Initio
• IB Extended Essay
• IB Theory of Knowledge
• University Applications
• Our Approach
• Happy Parents
• School Choice
• Become a Tutor

How to Write Your IB Biology Internal Assessment

By TutorsPlus

Performing well on the IB Internal Assessment requires a lot of work. This includes careful planning, research, experimentation, analysis, and writing. You should not take this assignment lightly since it accounts for 20% of your final grade. In this guide, we will explain in great detail how to write Biology IA to get a top score, so you can get the help you need every step along the way.

Our IB Biology Internal Assessment guide will cover both the necessary steps to take to conduct a successful investigation and the Biology IA structure.

What is the Biology Internal Assessment?

The IB Biology IA is a self-directed investigation into a Biology topic of your choice.

Your task is to design and conduct an experiment, analyse its results, and write a report about it. Typically, it takes around 10 hours of class time to work on the IA, but you will likely need to put in additional time outside of class. The final paper should be no longer than 3000 words.

A solid, well-designed IA can bring you a maximum of 24 points. To award these points, examiners take into account 4 marking criteria – learn more about them from this post .

The following guide on how to write Biology IA will show you how to meet these criteria and maximise your score. And remember, if you get stuck, our IB Biology tutors, teachers, and examiners are here to help.

The Five Steps to Writing IB Biology Internal Assessment

As we have already said, the Internal Assessment is one of the pillars of your end-of-the-course examination. Without completing your investigation, you cannot count on a good mark.

This means that you must treat your IB Biology IA as if you were a scientist for real, i.e. carefully plan what you’d like to do and which results you expect to obtain, carry out your experiment, and draw a conclusion. Here are these steps in more detail.

Choosing a Research Question

The first step is to choose a focused research question on a biological topic that interests you. The question should be specific enough to investigate through an experiment in the time available.

The best IB Biology Internal Assessments specify a clear reason why you chose such a topic. For example, you may investigate a biological phenomenon or issue that is relevant to the region where you live. Or it might be a topic that has fascinated you since childhood. Whatever your reasoning is, it must be clear from your work.

Still, it is not enough to choose a research question based solely on your interests. It should also be:

• Doable, i.e. you must be able to answer it taking into account time and resource limitations, as well as the level of complexity of an experiment;
• Measurable. In other words, your investigation should involve variables, which you can measure and analyse. It is also possible to work with statistical data.
• Unique. Your Biology IA doesn’t require you to do groundbreaking research. Nevertheless, you need to come up with an original question and contribute new insights to the chosen area of study.

Now sure which questions to use? Allow us to help you. We offer fresh 30+ IB Biology IA ideas . However, it is always best to use your own creative ideas, as examiners expect to see originality and thinking in your work.

Planning the Experiment

Once you have a research question, plan out how you are going to investigate it thoroughly. It is vital to consider every part of your work, from the variables you will measure, to the materials and methods you will use, and, of course, the data you aim to collect. 

However, before you begin to investigate, your teacher must approve your plan. Do not skip this step, as it could result in wasted time and effort if your teacher doesn’t agree with your IA proposal.

Conducting the Experiment

You need to carry out your experiment safely and systematically. Every observation and piece of data you obtain should be carefully recorded. It is important to repeat your experiment a few times to verify results as well as possibly find any errors and omissions in your methodology.

Analysing and Concluding

Examine your data to identify patterns and relationships. This data will help you draw conclusions to answer your original research question. For the best marks, you ought to discuss sources of error and suggest improvements for further investigation.

How to Write Biology IA: Structure and Points to Cover

When writing the IB Biology Internal Assessment, you need to follow a certain structure. A well-organised report will help ensure that you meet every marking criterion as well as demonstrate your thinking skills.

Here are our extensive guidelines for each section of your paper.

The Title and Contents Page

The Title Page sets the tone for the entire IB Biology Internal Assessment report. Your goal is to craft a descriptive title that reflects the purpose of the study. For example, “An Investigation into the Effect of X on Y.”

The title must be accompanied by a focused research question involving the key variables, units, time, and location, if applicable.

Below is an example of a title and a research question:

Title: The Influence of Light Intensity on the Rate of Photosynthesis in Elodea Plants.

Research Question: Does the intensity of light affect the rate of photosynthesis in Elodea (Elodea nuttallii), and if so, is there an optimal light intensity for maximizing photosynthetic activity?

Please note that if your experiment involves a living organism, you must identify it by both a common name and scientific name (genus and species).

When it comes to the Contents Page, it outlines the Biology IA structure and lists all sections and page numbers. This page is important to let examiners easily navigate the document.

Taking time with these initial pages will show your ability to be organised and thoughtful. The title and contents provide the first impression to evaluators.

Introduction

We suggest that you start your report with a brief overview of the topic and focus on its importance. For example, if your research involves a living organism or a compound, say where one might encounter it in everyday life, how we use it in food production or industrial processes, and explain the role it plays in an ecosystem.

Then, proceed from general to personal. What made you choose this topic and this research subject? Do they have a significance specifically for you or a global importance? Tell briefly about it at the beginning of your report.

Along with this, you should specify the method of investigation and why you used it. For instance, if you’re studying the effect of temperature on enzyme activity, you might want to use a sugar solution or specific chemical substrate to measure the enzyme’s effectiveness at different temperatures.

Overall, the introduction should be 0.5-1.0 pages long.

The next element of the appropriate IB Biology IA structure is background information. It helps understand the context of your research question and experiment.

For example, if you’re investigating a molecule, you need to describe its fundamental structure, i.e. identify its building blocks and how they are arranged. In case your subject is a consumable compound (such as capsaicin in chilli peppers or vitamin C), it is vital to discuss its effects on the body. You can explain their benefits and the potential harm associated with deficiencies or excessive consumption.

If your focus is a living organism, you need to pinpoint its key features and specify their impact on your experiment.

Often, IB Biology Internal Assessments involve reagents that react with a selected molecule or a compound. If you, too, have such reagents, explain their chemical structure and reactivity that make them suitable for your experiment. You shouldn’t forget to include relevant chemical equations.

It is not uncommon for Biology IAs to rely on secondary data instead of experiments. If you go this route, you must justify your choice of the specific database. Along with this, you should provide the data collection method and explain why this database is relevant to your research question.

If applicable, you can include diagrams, graphs, and other visual information. Don’t forget to cite the source you’re using and provide figure captions.

After you provide the scientific justification of your experiment, proceed to state your actual hypothesis. This should be an if-then statement outlining your testable prediction about the anticipated results.

Next, provide 2-3 sentences explaining your rationale. Link it logically to scientific principles and cite any research that informed your hypothesis. Your conclusion will either support your hypothesis or reject it.

Below is an example of a hypothesis:

“Exposure to different light intensities will affect the rate of photosynthesis in Elodea plants. I predict that as light intensity increases, the rate of photosynthesis will also increase due to the enhanced availability of light energy for the photosynthetic process. However, beyond this optimal level, I expect the rate of photosynthesis to plateau or even decrease due to factors like photoinhibition. This hypothesis is supported by the established principle that photosynthesis relies on light energy, and exceeding optimal light levels can damage photosynthetic machinery.”

Typically, biological investigations will involve three sets of variables: Independent, Dependent, and Controlled Variables:

• The independent variable is what you intentionally manipulate. You need to be highly specific about the increments tested.
• The dependent variable is what changes in response to manipulations. They are what you will be measuring.
• Controlled variables are held constant to isolate effects.

In your Internal Assessment, you need to list at least 5 control variables and do 15 repeats.

We suggest that you make a table with three columns introducing your variables. It must also feature units and, if applicable, ranges (for example, gas concentrations). Don’t forget to explain the instruments or methods you used to measure variables.

Your IA report must clearly show all the apparatus and equipment you used in your experiment.

To do so, you can draw and fully label a visual diagram of your experimental setup, especially detailing how the independent variable was implemented. For example, if testing temperature, show the water bath or incubator set at different temperatures.

Alternatively, you may take a photo of your actual lab setup and annotate it.

Either way, you must specify all the apparatus and instruments, as well as solutions and chemicals (with their concentrations) that your experiment requires. Whenever possible, discuss the uncertainties for your instruments (weighing balances, pipettes, etc.).

You can start this section with a Preliminary Experiment with the purpose of providing critical insights to guide the main investigation. You should explain how it shaped your methodology, analysis approach, and decision-making.

If you didn’t conduct a preliminary experiment, you need to research the independent variables and the method for measuring the dependent variable. This analysis will mimic the function of a preliminary experiment in informing the main investigation’s design.

The next important step is to write the experimental procedure in clear numbered steps. It is better to use the imperative mood to make it look like an instruction (“Heat the solution to 20 degrees Celsius …” instead of “I heated the solution…”). Make sure to include enough detail so that someone else would be able to repeat the process.

You need to include at least 5 increments of your independent variable (e.g. 5 temperatures) and a minimum of 5 trials/replicates per increment. Please keep in mind that your procedure should collect both quantitative data (numbers) and qualitative data (observational descriptions).

At the end of this section, it is important to discuss the risks involved in your experiment (such as safety, ethical, and environmental).

This section of your IB Biology Internal Assessment should include at least 3 data tables:

• Raw Data Table, which features only unprocessed numbers;
• Control Variables Table, which presents values of controlled variables, for instance, initial temperatures;
• Qualitative Data Table including observational descriptive details (for example, colour or temperature changes).

You need to give all these tables clear, descriptive titles. It is also essential to label all your columns with headings and units of measurement. You should make sure that your numbers are uniform, i.e. have the same decimal places. You are at risk of losing marks if you miss even a single unit.

We don’t recommend that you start your table on one page and continue on another. However, if you have a large table that doesn’t fit into a single page, you should repeat the title and column names after the split.

If your data is likely to come with uncertainties (for example, human reaction time), you can specify them in footnotes. You should also indicate equipment precision in column headings.

The analysis section of your Biology IA shows how you have used both qualitative and quantitative methods to support your arguments as well as identified and justified any discrepancies or errors in your data.

For starters, pick a sample of processed data to explain your calculations. You need to provide the equation you used and track each step to demonstrate how you converted raw numbers into analysed data. You should do it for every type of calculation (i.e. for averages, the volumes of gas obtained, etc.).

The rest of your results should be organised into fully labelled tables of calculated/processed data.

Next, you need to use this data to create 1-2 graphs with appropriate formats (for instance, bar, line, or scatter plots). All graphs must have titled axes with units and a figure legend. Below the graph, you should provide a description of trends.

It is more than likely that your data will feature uncertainties and errors – don’t try to hide them. In fact, you need to show that you understand, have reflected on, and can explain them. Best-fit lines and error bars can help you indicate these uncertainties and deviations. To maximise your final IA score, you should explain whether they are significant (how you know this), and how they impacted your results.

This section summarises the results of your experiment and answers your research question.

To begin with, provide your research question one more time to remind the reader about the aim of your experiment.

Then explain the trends obtained from your data, particularly within the graph. Make sure to be specific in your explanation. For example, instead of simply saying “temperature affected enzyme activity,” state something like “enzyme activity increased from a rate of 0.2 micromoles of substrate hydrolysed per minute at 20°C to a peak rate of 1.5 micromoles per minute at 40°C. This indicates a positive correlation between temperature and enzyme activity.”

Based on these conclusions, provide a clear answer to your research question and evaluate the extent to which it was answered. Did you achieve a complete answer, was it partial, or maybe you failed to confirm your hypothesis altogether? If you encountered any unexpected data points in your experiment, discuss these anomalies and suggest reasons for their occurrence.

If possible, you should compare your experimental values with established literature values. Cite your sources and explain how your findings align with or deviate from existing knowledge.

Finally, you need to discuss the impact of uncertainties associated with your measurements. Were these uncertainties significant to your experimental values? For example, a measurement of 10 grams with an uncertainty of ±0.01 gram is much more precise than an uncertainty of ±1 gram.

The final element of your Biology IA structure is supposed to demonstrate your critical thinking skills. In particular, it focuses on the strong and weak sides of your experiment.

We recommend that you identify at least 3 weaknesses or challenges in your experimental design, such as a lack of controls or a limited number of trials. Point out which errors were systematic, random, or human. Explain how each limitation impacts the quality and interpretation of your results.

If you provided error bars, ensure to explain what they demonstrate.

The next step is to propose at least 3 changes to improve the quality of your experimental design and data analyses. Those can include additional controlled variables, more replicates, different measurement techniques, increased precision on equipment, etc. Explain how each suggestion would specifically refine the experiment.

The last page of your IB Biology IA is a list of all the sources you utilised (textbooks, research, academic papers, etc.). You need to stick to the citation style recommended by your school.

Need Help to Write Biology IA? TutorsPlus are at Your Disposal

These were our suggestions on how to write Biology IA based on the new syllabus (the first assessment in 2025).

With 20% of your total grade, IB Biology Internal Assessment is a crucial aspect of your academic journey. It’s an opportunity to demonstrate your skills and improve your understanding of Biology. To ensure your IA report brings you the grade you hope for, you need to approach it with dedication, thoroughness, and a commitment to scientific excellence.

This journey can be quite stressful, but you don’t have to face it alone. At TutorsPlus, we understand the significance of your Internal Assessment and are here to support you every step of the way. Whether you need assistance in selecting a perfect topic, refining your methodology, or reviewing your biology IA structure or its content, our knowledgeable IB Biology tutors (who are simultaneously experienced teachers and examiners) are ready to guide you towards success.

Don’t hesitate to reach out to us for expert help and assistance. We are available at +41 022 731 8148 or [email protected]. With TutorsPlus by your side, you can turn your Internal Assessment into a remarkable achievement.

Sara has been an education consultant for TutorsPlus for 15 years, and is an expert on international IB education.  She is also a parent of two lively children.

Find a Tutor

Popular Posts

English IO – How to Ace Your IB English Literature & Language Oral

Tips to get a Top Grade in Your IGCSE English

How to get a top score in your IB TOK Exhibition

IGCSE Maths Revision Tips To Help You Today

What is the IA, EE or TOK? Everything you need to know about the IB written assignments

Maths Anxiety – How Parents Can Help 

More articles from our expert tutors.

IB French Language B: A Complete Guide

15 Mistakes to Avoid with IB Visual Arts Comparative Study

How To Crush Your IGCSE German Exam

Find a Tutor Today

" * " indicates required fields

Step 1 of 5

Find the best support for your family

Guide for Students to the IB Biology IA Format

Ah, the allure of the International Baccalaureate (IB) ! While involved with IB, I’ve noticed that mastering the IB Biology IA is no small feat. However, it’s not as intimidating as it might seem at first. This article reviews the essential IB Biology IA format and structure, sprinkled with insights from my years of experience.

When I first encountered the IB Biology IA, I was a tad overwhelmed. Yet, as I explored more, I realized its fundamental importance. So, what exactly is the IB Biology IA? It’s a key assessment piece for IB students that evaluates their experimental and investigative skills. Furthermore, proper format and structure can significantly impact your final grade. From my experience, laying a solid foundation is vital for success.

Critical Components of the IB Biology IA Format

The IA is a laboratory report that is an integral part of the IB Biology curriculum. For assessments through May 2025, this 6-12 page work should include a research question, detailed methodology, data interpretation, and a concluding section.

But to understand the intricacies of the IB Biology IA, we need to peel back the layers. In my years of experience, getting a grip on these elements has often been the turning point for many students.

So, understanding and perfecting these sections is instrumental in crafting a standout IB Biology IA . And believe me, with the right approach, it’s more than achievable!

Title Page and Research Question

The beginning is often the most crucial. Just as a book is judged by its cover, your IA begins its impression with the title page. It should be sharp and concise but comprehensive enough to provide an inkling of the direction of your investigation. Alongside, the research question is the backbone of your research, guiding every step. It’s paramount for it to be precise and well-defined, illuminating the research path for the reader. By the way, you can read more about the IB Internal Assessment format in our blog.

Introduction and Background

It is where you roll out the context, much like a red carpet for what follows. This section offers the essential backdrop, helping readers grasp the significance of your study. Going by the general IB criteria, it’s pivotal to elucidate the relevance and importance of your chosen topic here, providing a solid rationale for its investigation.

Personal Engagement and Exploration

This section is truly a window to your academic soul. It reveals your genuine interest, passion, and personal connection to the IB Biology topic . It’s a space to articulate why this particular topic resonated with you. Over the years, I’ve discerned that students who showcase genuine enthusiasm and curiosity here tend to elevate their IAs to a new level.

Methods and Materials

Venturing into the practical realm is where you lay out your experimental master plan. Document every apparatus, tool, and step taken during your research. The idea is to draft this section with such clarity and precision that anyone reading it could replicate your experiment seamlessly. 

So, the “Methods and Materials” section stands as your guidepost, shedding light on your experimental process. Here is an example of a step-by-step procedure:

• Preliminary Setup . Always start with how you prepared the lab space, ensuring all equipment was clean, sterile (if necessary), and within easy reach.
• Experiment Initiation . It could be preparing a solution, calibrating an instrument, or setting up the apparatus.
• Data Collection Phase . Describe in detail how you collected data, at what intervals, and using which tools. For example, “Using a calibrated pipette, I extracted 5ml of the solution every 10 minutes.”
• Safety Measures . Always document any safety protocols followed during the experiment, such as ensuring adequate ventilation or handling chemicals carefully.
• Experiment Conclusion . Detail how you wrapped up the experiment . It could include turning off equipment, safely disposing of materials, or storing data.
• Post-Experiment Cleanup . It is always a vital step to indicate how you restored the lab space to its original condition and how you stored or disposed of used materials.

The aim is to write this section thoroughly so that another student, perhaps halfway across the world, could read your description and carry out the same experiment with identical results. Clarity and meticulousness can raise your IA to a commendable standard.

Data Collection and Analysis

Ah, the realm of empirical evidence! As I’ve often reiterated in my interactions, this section forms the core of your IA. It’s where your observations and findings come alive. But numbers alone won’t suffice. Getting into analysis, identifying patterns, and drawing insightful conclusions is crucial. Precision and accuracy are the linchpins here.

Conclusion and Evaluation

This segment calls for introspection and a broad overview as we round off. Draw overarching inferences from your research, going beyond just stating the results. Understand the broader implications of your findings. Moreover, put on your critic’s glasses, judiciously assessing your study’s strengths while acknowledging its weaknesses.

Topics to Read:

• Understanding the IB Curriculum: A Beginner’s Guide
• Guide to the Official IBO Website for IB Student Advantages and Growth
• How to Manage Time Effectively as an IB Student
• How to Write a Strong IB IA Proposal?
• The Benefits of Pursuing the IB Diploma Programme
• What to Do if You Don’t Pass Your IB IA? How to Succeed Next Time?
• Can I Order IB Internal Assessment Written Online?

Tips for Excelling in Your IB Biology IA

The path to mastering the IB Biology IA can be challenging, but it can be a smooth ride with a few strategic pointers. Having been deeply involved with the IB for years, I’ve collected vital insights that can distinguish between a satisfactory and a stellar IA . Let’s get right into them.

1. Selecting a Relevant Research Question

The foundation of your entire IA is your research question. What’s the secret sauce to crafting the perfect one? It’s all about relevance. Ensure that your question aligns neatly with the biology syllabus.

From my numerous sessions and interactions, a research question that resonates well with the core curriculum often garners more appreciation. Finding that sweet spot between ambition and practicality is also pivotal. While aiming high is commendable, choosing a feasible question within your means and resources is crucial.

2. Prioritizing Accurate Data Collection

Data is the heartbeat of your IA. Precise collection is non-negotiable. Here’s a valuable piece of advice I’ve echoed throughout my years — always double, if not triple, check your data. A minor mistake can alter your results significantly. Consistency is vital in this aspect. Make sure your data collection methods are systematic, repeatable, and free of any biases.

3. Emphasizing Personal Engagement

It is where your unique touch makes a difference. The IA isn’t just about presenting facts but also about your connection and enthusiasm for the topic. Standout IAs often have a strong undercurrent of genuine interest and dedication. From my vast experience, when students infuse their work with sincere passion, it shines through, making the IA genuinely memorable:

• Initial Curiosity . Begin by shedding light on what piqued your interest in the topic.
• Challenges and Overcoming Them . Maybe you faced difficulty sourcing materials or grappled with a particular concept.
• Moments of Eureka . Highlight instances during your research when things clicked, or you experienced breakthrough moments.
• Personal Stories . You may have always been fascinated by plant biology because you used to garden with a family member, or perhaps a unique health challenge drove your interest in human biology.
• Reflections . Share your introspective moments. How has this research changed or deepened your understanding of the topic? How has it influenced your perspective or future aspirations in biology?

Remember, the personal engagement section is your canvas. It’s an opportunity to paint a picture of the researcher and the individual behind the research. By emphasizing these elements, you elevate the depth of your IA and create a resonant narrative that reviewers and readers can connect with.

4. Reflection and Evaluation of Your Findings

After all the rigorous work, it’s essential to pause and reflect. It involves not merely stating your results but also pondering their significance. How do your findings fit into the larger framework of biological understanding? Additionally, always be ready to assess your work critically. Pinpoint areas of improvement and suggest potential refinements. Such a holistic perspective adds depth to your IA and showcases your understanding and maturity.

Don’t let the stress of choosing an IA topic hold you back.

Are you struggling to come up with topic suggestions for your IB Internal Assessment?

Our experienced writers can help you choose the perfect topic for your IA

Tailored to your specific subject and requirements.

Simply click:

Common Mistakes to Avoid in IB Biology IA Structure

Over the years, I’ve seen students make the same mistakes. Let’s ensure you’re not one of them!

1. Skipping Peer Review and Feedback

In the thick of research and writing, it’s easy to become myopic and miss out on tiny errors or areas of improvement. That’s where a second set of eyes becomes invaluable. Peer reviews or feedback from mentors can offer fresh perspectives, identify overlooked mistakes, or even provide insights that can elevate the quality of your work. From my experience, students who embrace feedback often end up with more polished and well-rounded IAs.

2. Inconsistent Data Collection Methods

While the methodology might be sound, inconsistency in data collection can introduce significant errors. Maintaining uniformity throughout the data collection phase is crucial. For instance, if you’re measuring plant growth, ensuring that measurements are taken simultaneously, under the same conditions, can make a difference.

3. Neglecting the Significance of the Research Question

The research question is the north star of your IA. Sometimes, students opt for broad or overly ambitious questions, convoluting the research process. It’s essential to choose a question that’s both relevant and feasible, ensuring that it aligns with the IB Biology syllabus and is achievable within the scope of the IA.

4. Not Justifying Methodological Choices

Simply listing out methods isn’t enough. It’s crucial to explain why a particular way was chosen and its relevance to the research question. Offering a rationale can give depth to the methodology section and showcase a deeper understanding of the research process.

Conclusion: Perfecting Your IB Biology IA

The IB Biology IA format and structure might seem daunting initially, but it becomes manageable with the proper guidance and preparation. I believe that with dedication and focus, every student can succeed in their IB Biology IA. Remember, it’s a marathon, not a sprint. 

In conclusion, with the right approach and these strategic tips in your arsenal, the path to creating an impressive IB Biology IA becomes much more straightforward. Combine these insights with dedication, and you’re on your way to success! Here’s wishing you all the very best! And remember, you can always get help with IB Biology IA from our experienced writers.

Get hot offers and discounts for your IB Assignments

Our writing solutions cater to all disciplines within the IB program, and we specialize in crafting academic papers for students of all levels. We follow the IB criteria.

Adhering strictly to the rigorous standards set by the IB, we deploy a methodical approach to our writing process. This ensures that every piece of content we generate not only meets but exceeds the expectations set within the program.

Contact us:

[email protected]

[email protected]

Latest Articles:

Interdisciplinary Topics in Extended Essays. Ideas for IB Students

How to Write a Conclusion for Your IB Extended Essay? Tips and Tricks

How to Write a Body Section for Your IB Extended Essay?

Our services:.

• Buy Internal Assessment
• Buy Math IA
• Buy Extended Essay
• Buy TOK Essay
• Buy TOK Exhibition

IBWritingService.com is an independent academic writing aid with no official ties to the International Baccalaureate Organization (IBO). Our use of “IB” in the domain and title is purely for identification, and we neither claim nor imply any endorsement or partnership with the IBO. Our services aim to support students’ educational needs without violating IBO policies. Trademarks mentioned are property of their owners and do not suggest affiliations. By using our services, you acknowledge our non-affiliation with the IBO and that we’re not a substitute for IBO requirements. We deny any liability for use of our services in relation to the IBO.

ALL PAPERS WRITTEN BY OUR EXPERTS AS PART OF THIS WRITING SERVICE ARE FOR REFERENCE PURPOSES ONLY. WHEN USING CONTENT PURCHASED FROM THIS WEBSITE, IT MUST BE PROPERLY REFERENCED.

• Terms & Conditions
• Revision Policy
• Privacy Policy
• Refund Policy
• Cookie Policy

© 2024. All Rights Reserved.

IB Biology IA: 60 Examples and Guidance

Charles Whitehouse

The International Baccalaureate (IB) program offers a variety of assessments for students, including Internal Assessments (IAs), which are pieces of coursework marked by students’ teachers. The Biology IA is an assessment designed to test students' understanding of the material they have learned in their biology course, their ability to conduct independent research, and their competence in applying their knowledge to real-world biological issues.

What is the IA?

The IA consists of a laboratory report that students must complete during their IB biology course. For assessments before May 2025, the report should be 6 to 12 pages in length, but after May 2025, the length requirement is updated to a maximum of 3,000 words.

📈Boost your grades with our revision platform, used by 100,000+ students! 📝Access thousands of practice questions, study notes, and past papers for every subject. 📚 View IB Resources 📚 View A-Level Resources 📚 View GCSE Resources 📚 View IGCSE Resources

What should the IA contain?

The research question for the internal assessment should be a testable question that is related to the biology curriculum. It's essential that the question is relevant to the biology curriculum, specific and clearly defined. The methodology section should explain how the research was conducted, including the materials and methods used. The methodology should be detailed and well-explained, and should include information on the materials and methods used, as well as any ethical considerations.

Data analysis is an important aspect of the IA. Professional IB Biology tutors recommend that students should present their data in a clear and organized manner, and should use appropriate statistical analysis to interpret their results. They should also make sure to include a discussion of the limitations of their study and the implications of their findings.

The conclusion should summarise the main findings of the study, relate the results back to the research question, and address the relevance of these findings to the broader context of the biological field.

In addition to the laboratory report, students must complete a reflective statement, which is mandatory. This statement should be around 500 words long and must include references to how the student has achieved specific learning objectives outlined in the IB Biology syllabus, and should reflect on the student’s learning during the internal assessment process. The reflective statement should include a description of the student’s personal learning process, including successes and challenges, as well as an evaluation of their performance on the internal assessment and the skills they have gained through the process.

Have a look at our comprehensive set resources for IB Biology developed by expert IB teachers and examiners!

- IB Biology 2024 Study Notes

- IB Biology 2025 Study Notes

- IB Biology 2024 Questions

- IB Biology 2025 Questions

What are some example research questions?

Here are examples with details of potential research questions, written by expert IB Biology tutors and teachers, that could inspire your Biology IA:

1 - Investigating the effect of different types of sugars on the rate of fermentation by yeast. To investigate the effect of different concentrations of a specific herbicide on the growth rate of a particular plant species, one could set up an experiment in which the plants are grown in soil with varying concentrations of the herbicide. An appropriate range of concentrations and a suitable plant species would need to be chosen, along with control variables such as light, temperature, and watering. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of the herbicide on the plant's growth.

2 - How does the pH of a solution affect the activity of an enzyme? To investigate the effect of pH on enzyme activity, one could set up an experiment in which the enzyme is exposed to solutions with varying pH levels. The enzyme's activity could be measured by monitoring the rate of a specific reaction catalyzed by the enzyme. Control variables such as temperature, substrate concentration, and enzyme concentration would need to be kept constant. By comparing the activity of the enzyme at different pH levels, the optimal pH range for the enzyme could be determined.

3 - Can the concentration of vitamin C in different types of fruit juice be determined using titration?

To determine the concentration of vitamin C in different types of fruit juice using titration, a standardized solution of a known concentration of potassium permanganate would be prepared. A sample of the fruit juice would be titrated with the potassium permanganate solution until the endpoint is reached, indicating that all the vitamin C has reacted with the potassium permanganate. The concentration of vitamin C in the fruit juice can then be calculated based on the volume and concentration of the potassium permanganate solution used in the titration. This process would need to be repeated for each type of fruit juice being tested.

4 - Investigating the effect of light intensity on the rate of photosynthesis in aquatic plants.

Set up an experiment in which aquatic plants are placed in containers with varying levels of light intensity. The light intensity could be controlled by adjusting the distance between the light source and the plants. The rate of photosynthesis could be measured by tracking the amount of oxygen produced by the plants over a set period of time. Comparing the rates of photosynthesis of the different groups would determine the impact of light intensity on the plant's photosynthetic activity. Control variables such as temperature, water quality, and plant species would need to be kept constant.

5 - How does the concentration of carbon dioxide affect the rate of photosynthesis in terrestrial plants?

Conduct an experiment in which plants are grown under different concentrations of carbon dioxide. The plants would need to be grown in a controlled environment with consistent light, temperature, and watering. The rate of photosynthesis could be measured by monitoring the oxygen production of the plants using a dissolved oxygen probe. The results could then be analyzed to determine how the concentration of carbon dioxide affects the rate of photosynthesis in terrestrial plants.

6 - Can the presence of glucose in urine be determined using Benedict's test?

Collect a urine sample from the individual being tested. Add Benedict's reagent to the sample and heat it in a water bath. If glucose is present in the urine, it will react with the Benedict's reagent and cause a color change. The intensity of the color change can be compared to a color chart to determine the concentration of glucose in the urine. This process would need to be repeated for each urine sample being tested.

7 - Investigating the effect of temperature on the respiration rate of germinating seeds.

Set up an experiment in which germinating seeds are exposed to different temperatures. The respiration rate of the seeds could be measured by monitoring the amount of oxygen consumed or carbon dioxide produced over a set period of time. The experiment would need to control for other variables such as the type of seed, the amount of water and nutrients provided, and the length of time the seeds have been germinating. Comparing the respiration rates of the different groups would determine the effect of temperature on the seeds' respiration rate.

8 - How does the concentration of salt in a solution affect the growth of bacteria?

Prepare a series of solutions with varying concentrations of salt, and inoculate each with a known amount of bacteria. The solutions would need to be incubated at a constant temperature for a set period of time, and the growth of the bacteria could be measured by counting the number of colonies or by using a spectrophotometer to measure the optical density of the solution. Comparing the growth rates of the bacteria in the different salt concentrations would determine the effect of salt on bacterial growth. Control variables such as pH, temperature, and nutrient availability would need to be kept constant.

9 - Can the concentration of nitrogen compounds in soil be determined using colorimetry?

Collect soil samples from different locations and extract the nitrogen compounds using a suitable method such as Kjeldahl digestion. The extracted compounds can then be analyzed using colorimetry, which involves adding a reagent that reacts with the nitrogen compounds and produces a color. The intensity of the color can be measured using a spectrophotometer, and the concentration of nitrogen compounds in the soil can be calculated based on the absorbance of the color. This process would need to be repeated for each soil sample being tested.

10 - Investigating the effect of different types of plant hormones on the growth of seedlings.

Set up an experiment in which seedlings are grown in different concentrations of plant hormones, with control variables such as light, temperature, and watering. The growth rate of the seedlings could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of the plant hormones on the seedlings' growth. The experiment could also include observations of other plant characteristics such as leaf size and color, root development, and overall health.

Get expert help with your IB Biology

The world's leading online IB Biology tutoring provider trusted by students, parents, and schools globally.

4.93 /5 based on 509 reviews

11 - How does the concentration of salt in water affect the hatching rate of brine shrimp?

Set up multiple containers with different concentrations of salt water and add brine shrimp eggs to each container. The containers should be kept at a consistent temperature and light level. After a set period of time, count the number of hatched brine shrimp in each container and calculate the hatching rate. Comparing the hatching rates of the different containers would determine the effect of salt concentration on the hatching rate of brine shrimp.

12 - Can the rate of mitosis be determined using microscopy techniques?

Collect a sample of cells undergoing mitosis and prepare them for microscopy. Using a microscope, observe the cells and record the time it takes for each cell to complete each stage of mitosis. The rate of mitosis can then be calculated by dividing the time taken for each stage by the total time taken for the entire process. This process would need to be repeated for multiple cells to ensure accuracy and reliability of the results.

13 - Investigating the effect of different types of antibiotics on the growth of bacteria.

Culture bacteria in petri dishes with different concentrations of antibiotics. The growth of the bacteria can be observed and measured over a set period of time. The concentration of antibiotic that inhibits the growth of the bacteria can be determined, and the effectiveness of different types of antibiotics can be compared. Control variables such as temperature, humidity, and nutrient availability would need to be kept constant to ensure accurate results.

14 - How does the concentration of oxygen affect the respiration rate of crickets?

Set up a series of chambers with different concentrations of oxygen, ranging from low to high. Place crickets in each chamber and monitor their respiration rate by measuring the amount of oxygen consumed and carbon dioxide produced over a set period of time. The results can be analyzed to determine the effect of oxygen concentration on the respiration rate of crickets. Control variables such as temperature and humidity would need to be kept constant throughout the experiment.

15 - Can the concentration of glucose in blood be determined using glucose oxidase and spectrophotometry?

A sample of blood would be mixed with glucose oxidase, which converts glucose to hydrogen peroxide. The amount of hydrogen peroxide produced is proportional to the amount of glucose in the sample. A spectrophotometer would then be used to measure the absorbance of the sample at a specific wavelength, which is also proportional to the amount of hydrogen peroxide present. The concentration of glucose in the blood sample can then be calculated based on the absorbance reading and a standard curve generated using known concentrations of glucose. This process would need to be repeated for each blood sample being tested.

16 - Investigating the effect of different types of pesticides on the growth of bean plants.

Set up an experiment in which bean plants are grown in soil treated with varying concentrations of different pesticides. An appropriate range of concentrations and a suitable plant species would need to be chosen, along with control variables such as light, temperature, and watering. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of the pesticides on the plant's growth. Additionally, the health of the plants could be assessed by examining their leaves for signs of damage or discoloration.

17 - How does the concentration of light affect the growth of algae?

Set up multiple containers with different concentrations of light, ranging from low to high. In each container, add a sample of algae and monitor their growth over a set period of time. The growth rate of the algae can be measured by tracking their biomass or chlorophyll content. Comparing the growth rates of the different groups would determine the impact of light concentration on the growth of algae. Control variables such as temperature, nutrient availability, and water quality would need to be maintained to ensure accurate results.

18 - Can the presence of starch in leaves be determined using iodine solution?

Obtain a sample of the leaf and grind it into a fine powder. Add a few drops of iodine solution to the powder and observe the color change. If the solution turns blue-black, it indicates the presence of starch in the leaf. This process would need to be repeated for multiple leaves from different plants to ensure accuracy and reliability of the results. Control variables such as the age of the leaf and the time of day the sample is taken should also be considered.

19 - Investigating the effect of different types of plant nutrients on the growth of tomatoes.

Set up an experiment in which tomato plants are grown in soil with varying concentrations of different plant nutrients, such as nitrogen, phosphorus, and potassium. Control variables such as light, temperature, and watering would need to be maintained. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of the plant nutrients on the plant's growth. Additionally, the nutrient content of the tomato plants could be analyzed to determine if there is a correlation between the nutrient concentration in the soil and the nutrient content in the plant.

20 - How does the concentration of carbon dioxide affect the growth of marine plants?

Conduct an experiment in which marine plants are grown in water with varying concentrations of carbon dioxide. The carbon dioxide concentration could be controlled by bubbling different amounts of carbon dioxide gas into the water. The growth rate of the plants could be measured by tracking their height, mass, or chlorophyll content over a set period of time. Comparing the growth rates of the different groups would determine the impact of carbon dioxide concentration on the plant's growth. Other variables such as light, temperature, and nutrient availability would need to be controlled to ensure that any differences in growth rate are due to the carbon dioxide concentration.

21 - Can the concentration of protein in an egg be determined using the Biuret method?

To determine the concentration of protein in an egg using the Biuret method, the egg would need to be homogenized and the protein extracted. A Biuret reagent would then be added to the protein extract, which would cause a color change if protein is present. The intensity of the color change would be proportional to the concentration of protein in the egg. A standard curve could be created using known concentrations of protein to determine the concentration of protein in the egg sample. This process would need to be repeated for each egg being tested.

22 - Investigating the effect of different types of plant hormones on the root growth of seedlings.

Set up an experiment in which seedlings are grown in soil with different concentrations of plant hormones. An appropriate range of concentrations and a suitable plant species would need to be chosen, along with control variables such as light, temperature, and watering. The root growth of the seedlings could be measured by tracking their length or mass over a set period of time. Comparing the root growth of the different groups would determine the impact of the plant hormones on the seedling's root growth.

23 - How does the concentration of oxygen affect the respiration rate of goldfish?

Set up multiple tanks with goldfish and varying levels of oxygen concentration. The respiration rate of the goldfish can be measured by tracking their oxygen consumption or carbon dioxide production. The experiment would need to be conducted over a set period of time with control variables such as temperature and feeding schedules. Comparing the respiration rates of the different groups would determine the effect of oxygen concentration on the goldfish's respiration rate.

24 - Can the concentration of a specific hormone in blood be determined using ELISA?

ELISA (enzyme-linked immunosorbent assay) involves coating a microplate with a specific antibody that binds to the hormone of interest. The sample of blood is then added to the plate, and any hormone present in the sample will bind to the antibody. A secondary antibody that is linked to an enzyme is then added, which will bind to the hormone-antibody complex. The enzyme will then catalyze a reaction that produces a detectable signal, such as a color change. The intensity of the signal is proportional to the amount of hormone present in the sample, allowing for the concentration of the hormone to be determined. A standard curve can be created using known concentrations of the hormone to accurately quantify the concentration in the sample.

25 - Investigating the effect of different types of pollutants on the growth of watercress.

Set up an experiment in which watercress plants are grown in water contaminated with different types and concentrations of pollutants. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of the pollutants on the plant's growth. Control variables such as light, temperature, and watering would need to be kept constant to ensure accurate results. The types and concentrations of pollutants used in the experiment would need to be carefully chosen based on their potential impact on watercress growth and their relevance to real-world pollution scenarios.

26 - How does the concentration of light affect the rate of respiration in germinating seeds?

Set up a series of experiments in which germinating seeds are exposed to different intensities of light. The rate of respiration could be measured by tracking the amount of oxygen consumed or carbon dioxide produced by the seeds over a set period of time. The experiment would need to control for other variables such as temperature and humidity. Comparing the rates of respiration for the different light intensities would determine the impact of light concentration on the rate of respiration in germinating seeds.

27 - Can the concentration of nitrates in water be determined using colorimetry?

Prepare a series of standard solutions of known concentrations of nitrates. A sample of the water would be mixed with a reagent that reacts with nitrates to produce a colored product. The intensity of the color would be measured using a colorimeter, and the concentration of nitrates in the water can be calculated based on the intensity of the color and the concentration of the standard solutions. This process would need to be repeated for each water sample being tested.

28 - Investigating the effect of different types of disinfectants on the growth of bacteria.

Prepare a culture of bacteria and divide it into multiple groups. Each group would be exposed to a different type of disinfectant, while control groups would not be exposed to any disinfectant. The growth rate of the bacteria in each group would be measured over a set period of time, either by counting the number of colonies or by measuring the turbidity of the culture. Comparing the growth rates of the different groups would determine the effectiveness of each disinfectant on inhibiting bacterial growth.

29 - How does the concentration of salt in water affect the growth of duckweed?

Set up multiple containers of water with varying concentrations of salt. Add duckweed to each container and monitor their growth over a set period of time. The growth rate of the duckweed can be measured by tracking their surface area or biomass. Comparing the growth rates of the different groups would determine the impact of salt concentration on the growth of duckweed. Control variables such as light, temperature, and nutrients should be kept constant across all containers.

30 - Can the concentration of ethanol in different types of alcoholic beverages be determined using gas chromatography?

Use gas chromatography to separate the components of the alcoholic beverage sample. The ethanol would be detected and quantified using a detector such as a flame ionization detector. The concentration of ethanol in each sample can then be calculated based on the peak area or height of the ethanol peak in the chromatogram. This process would need to be repeated for each type of alcoholic beverage being tested.

31 - Investigating the effects of different types of exercise on heart rate and blood pressure.

Recruit a group of participants and randomly assign them to different exercise groups (e.g. running, cycling, weightlifting). Measure their heart rate and blood pressure before and after the exercise session. Repeat this process for each exercise group. Analyze the data to determine if there are any significant differences in the effects of the different types of exercise on heart rate and blood pressure. Control variables such as age, gender, and fitness level should be taken into account.

32 - How does the level of noise pollution affect the behavior and communication of animals?

Conduct a field study in which the behavior and communication of animals in areas with varying levels of noise pollution are observed and recorded. Control variables such as time of day, weather conditions, and animal species would need to be taken into account. The observations could include changes in vocalizations, movement patterns, and social interactions. Comparing the behavior and communication of animals in areas with different levels of noise pollution would determine the impact of noise on their behavior. Statistical analysis could be used to establish correlations between noise levels and changes in animal behavior.

33 - Investigating the effects of different types of fertilizers on plant growth and nutrient uptake.

Set up an experiment in which identical plants are grown in soil with different types of fertilizers. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Nutrient uptake could be measured by analyzing the nutrient content of the plants at the end of the experiment. Comparing the growth rates and nutrient uptake of the different groups would determine the impact of the fertilizers on plant growth and nutrient uptake. Control variables such as light, temperature, and watering would need to be kept constant.

34 - How does exposure to light pollution affect the migration and behavior of nocturnal animals?

Conduct a field study in which nocturnal animals are observed in areas with varying levels of light pollution. The behavior and migration patterns of the animals could be tracked using GPS or radio telemetry. Data on the animals' activity levels, movement patterns, and habitat use could be collected and compared between areas with different levels of light pollution. This would allow for an assessment of the impact of light pollution on nocturnal animals and their ecosystems.

35 - Investigating the effects of different types of water pollution on aquatic ecosystems and organisms.

Set up multiple tanks or containers with different types and levels of water pollution, such as oil spills, chemical runoff, or excess nutrients. Populate each tank with a variety of aquatic organisms, such as fish, algae, and invertebrates. Monitor the health and behavior of the organisms over a set period of time, noting any changes in growth, reproduction, or mortality rates. Comparing the results from each tank would allow for an assessment of the impact of different types of water pollution on aquatic ecosystems and organisms.

36 - How does exposure to electromagnetic radiation affect the growth and development of plants?

Set up an experiment in which plants are exposed to different levels of electromagnetic radiation, such as UV light or radio waves. The plants would need to be grown in a controlled environment with consistent light, temperature, and watering. The growth rate and development of the plants could be measured by tracking their height, leaf size, and overall health over a set period of time. Comparing the growth and development of the plants exposed to different levels of electromagnetic radiation would determine the impact of the radiation on the plants. Control groups of plants not exposed to radiation would also need to be included for comparison.

37 - Investigating the effects of different types of air pollution on respiratory function and lung health.

Recruit a sample of participants who are exposed to different types of air pollution, such as those who live near busy roads or industrial areas. Conduct lung function tests, such as spirometry, on each participant to establish a baseline measurement of their respiratory health. Repeat the tests after a set period of time to determine any changes in lung function. Comparing the results of participants exposed to different types of air pollution would determine the impact of each type on respiratory function and lung health. Other factors, such as age and smoking status, would need to be controlled for in the analysis.

38 - How does the level of acidity affect the growth and survival of aquatic organisms?

Conduct experiments in which aquatic organisms are exposed to different levels of acidity. The organisms could be placed in tanks with varying pH levels, and their survival and growth rates could be monitored over time. Control variables such as temperature, light, and food availability would need to be kept constant. Comparing the survival and growth rates of the different groups would determine the impact of acidity on the organisms. Additionally, other factors such as changes in behavior or reproduction could also be observed and analyzed.

39 - Investigating the effects of different types of food additives on human health and metabolism.

Conduct a literature review to identify the potential health effects of different food additives. Design a study in which participants consume a controlled diet with varying levels of the food additives being tested. Blood and urine samples could be collected at regular intervals to measure changes in metabolism and biomarkers of health. Statistical analysis would be used to determine if there are significant differences in health outcomes between the different groups.

40 - How does the level of UV radiation affect the growth and survival of plants?

Set up an experiment in which plants are grown under different levels of UV radiation. This could be achieved by using UV lamps of varying intensities or by placing the plants at different distances from a natural source of UV radiation, such as the sun. The growth rate, survival rate, and other relevant factors such as leaf size and chlorophyll content could be measured and compared across the different groups. This would help determine the impact of UV radiation on plant growth and survival. Control variables such as temperature, humidity, and watering would need to be carefully monitored and controlled to ensure accurate results.

41 - Investigating the effects of different types of drugs on human physiology and behavior.

Conduct a double-blind, randomized controlled trial with a group of participants who are given different types of drugs. The physiological and behavioral effects of the drugs would be measured through various tests and assessments, such as blood pressure, heart rate, cognitive function, and mood. The results would be analyzed to determine the impact of each drug on the participants' physiology and behavior, and any potential side effects or risks associated with each drug would be identified.

42 - How does the level of carbon dioxide affect the growth and development of plants?

Conduct an experiment in which plants are grown in controlled environments with varying levels of carbon dioxide. The growth rate, height, and biomass of the plants can be measured over a set period of time. The results can be compared to determine the impact of different levels of carbon dioxide on plant growth and development. Other variables such as light, temperature, and watering would need to be controlled to ensure that the results are accurate and reliable.

43 - Investigating the effects of different types of pesticides on non-target organisms and ecosystems.

Conduct a series of experiments in which different non-target organisms are exposed to varying concentrations of the pesticide. The organisms could be chosen based on their ecological importance, such as pollinators or soil microorganisms. The effects of the pesticide on the organisms could be measured by tracking their survival rates, reproductive success, or behavior. Additionally, the impact of the pesticide on the broader ecosystem could be assessed by monitoring changes in the abundance and diversity of other species in the area. Comparing the results of these experiments would provide insight into the potential ecological risks associated with the use of the pesticide.

44 - How does the level of atmospheric pollutants affect the growth and development of plants?

Set up an experiment in which plants are grown in controlled environments with varying levels of atmospheric pollutants, such as nitrogen dioxide or ozone. The growth rate, leaf area, and chlorophyll content of the plants could be measured over a set period of time. Comparing the growth rates and health of the plants exposed to different levels of pollutants would determine the impact of atmospheric pollutants on plant growth and development. Control variables such as light, temperature, and watering would need to be kept constant to ensure accurate results.

45 - Investigating the effects of different types of microorganisms on the digestive system and gut microbiome.

Conduct a study in which different groups of animals are exposed to different types of microorganisms, either through their diet or through direct exposure. The effects on their digestive system and gut microbiome could be measured through various methods such as analyzing fecal samples, measuring changes in gut pH, or monitoring the presence of certain bacteria. Comparing the results from the different groups would determine the impact of the microorganisms on the animals' digestive system and gut microbiome.

46 - How does the level of humidity affect the growth and survival of insects?

Conduct an experiment in which insects are exposed to different levels of humidity in a controlled environment. The survival rate and growth rate of the insects could be measured over a set period of time. The experiment would need to control for other variables such as temperature, food availability, and lighting. Comparing the survival and growth rates of the insects in different humidity levels would determine the impact of humidity on their growth and survival.

47 - Investigating the effects of different types of radiation on the genetic material and DNA replication.

Cultivate a sample of cells in a controlled environment and expose them to different types of radiation, such as gamma rays or UV light. The cells would then be monitored for changes in their genetic material, such as mutations or damage to DNA replication. The results could be compared to a control group that was not exposed to radiation to determine the effects of each type of radiation on the cells. Additional experiments could be conducted to investigate the long-term effects of radiation exposure on the cells.

48 - How does the level of soil salinity affect the growth and survival of plants?

Set up an experiment in which plants are grown in soil with varying levels of salinity. An appropriate range of salinity levels and a suitable plant species would need to be chosen, along with control variables such as light, temperature, and watering. The growth rate and survival rate of the plants could be measured by tracking their height, mass, and number of leaves over a set period of time. Comparing the growth and survival rates of the different groups would determine the impact of soil salinity on the plant's growth and survival. Additionally, the concentration of ions in the soil could be measured to determine the relationship between soil salinity and plant growth.

49 - Investigating the effects of different types of antibiotics on bacterial growth and antibiotic resistance.

Set up a series of petri dishes with agar and bacterial cultures. Each dish would contain a different antibiotic, with varying concentrations. The dishes would be incubated for a set period of time, and the growth of the bacteria would be measured. The results would show which antibiotics were most effective at inhibiting bacterial growth, and whether any resistance had developed. Control variables such as temperature, humidity, and the type of bacteria used would need to be carefully controlled to ensure accurate results.

50 - How does the level of soil pH affect the growth and survival of plants?

Conduct an experiment in which plants are grown in soil with varying pH levels. An appropriate range of pH levels and a suitable plant species would need to be chosen, along with control variables such as light, temperature, and watering. The growth rate of the plants could be measured by tracking their height or mass over a set period of time. Comparing the growth rates of the different groups would determine the impact of soil pH on the plant's growth and survival. Other factors such as nutrient availability and toxicity would also need to be considered and controlled for in the experiment.

51 - Investigating the effects of different types of hormones on animal behavior and physiology.

Conduct experiments with different groups of animals, each exposed to a different hormone. The behavior and physiology of the animals would be monitored and recorded over a set period of time. Control variables such as diet, environment, and age would need to be maintained across all groups. Comparing the results of the different groups would determine the effects of each hormone on the animals' behavior and physiology. Statistical analysis could be used to determine the significance of the results.

52 - How does the level of water availability affect the growth and survival of plants?

Conduct an experiment in which plants are grown in different levels of water availability, ranging from drought conditions to optimal watering. The growth rate, survival rate, and overall health of the plants would be monitored over a set period of time. The data collected would be used to determine the impact of water availability on plant growth and survival. Control variables such as light, temperature, and soil type would need to be kept constant to ensure accurate results.

53 - Investigating the effects of different types of plant extracts on bacterial growth and antibiotic resistance.

Prepare bacterial cultures in petri dishes with different concentrations of the plant extracts. The growth of the bacteria can be observed over a set period of time, and the effectiveness of the plant extracts in inhibiting bacterial growth and antibiotic resistance can be determined by comparing the growth rates of the different groups. Control variables such as temperature and nutrient availability would need to be kept constant to ensure accurate results.

54 - How does the level of nutrients affect the growth and development of microorganisms?

Conduct experiments in which microorganisms are grown in nutrient-rich and nutrient-poor environments. The growth rate and development of the microorganisms could be measured by tracking their population size and observing their morphology under a microscope. Comparing the growth rates and morphology of the microorganisms in the different environments would determine the impact of nutrient levels on their growth and development. Control variables such as temperature, pH, and oxygen levels would need to be kept constant.

55 - Investigating the effects of different types of pollution on the reproductive systems and fertility of animals.

Select a suitable animal species and expose them to different types of pollution, such as air pollution or water pollution. The reproductive systems and fertility of the animals could be monitored over a set period of time, and compared to a control group that was not exposed to pollution. The impact of the pollution on the animals' reproductive systems and fertility could be determined by analyzing factors such as the number of offspring produced, the health of the offspring, and any abnormalities or complications observed during pregnancy or birth.

56 - How does the level of light intensity affect the growth and development of microorganisms?

Set up multiple petri dishes with agar and different levels of light intensity, ranging from complete darkness to bright light. Inoculate each dish with the same strain of microorganisms and incubate them for a set period of time. The growth of the microorganisms can be measured by counting the number of colonies or by measuring the turbidity of the culture. Comparing the growth rates of the different groups would determine the impact of light intensity on the growth and development of the microorganisms. Control variables such as temperature, nutrient availability, and humidity would need to be maintained throughout the experiment.

57 - Investigating the effects of different types of food on the metabolism and energy balance of humans.

Conduct a randomized controlled trial in which participants are assigned to different groups and given different types of food to eat for a set period of time. The participants' energy intake, metabolism, and weight would be measured before and after the intervention to determine the impact of the different types of food on their energy balance. Other factors such as physical activity levels and sleep patterns would also need to be controlled for to ensure accurate results.

58 - How does the level of nutrients affect the growth and development of plants?

Conduct an experiment in which plants are grown in different nutrient solutions with varying levels of nitrogen, phosphorus, and potassium. The growth rate, height, and mass of the plants could be measured over a set period of time to determine the impact of the nutrient levels on their growth and development. Control variables such as light, temperature, and watering would need to be kept constant. The results could be analyzed to determine the optimal nutrient levels for plant growth and development.

59 - Investigating the effects of different types of hormones on plant growth and development.

Set up an experiment in which different groups of plants are treated with different types and concentrations of hormones. The growth rate, height, and mass of the plants could be measured over a set period of time. Control variables such as light, temperature, and watering would need to be kept constant. Comparing the growth rates of the different groups would determine the impact of the hormones on the plant's growth and development. Additional measurements such as leaf size, root length, and flower production could also be taken to further analyze the effects of the hormones.

60 - How does the level of water quality affect the growth and survival of aquatic organisms?

Set up multiple aquariums with varying levels of water quality, such as different levels of pollutants or pH. Introduce the same species of aquatic organism into each aquarium and monitor their growth and survival over a set period of time. The growth rate and survival rate of the organisms can be compared between the different aquariums to determine the impact of water quality on their growth and survival. Control variables such as temperature and feeding schedules should be kept consistent across all aquariums.

Remember to come up with your own original IA topic and check it with your teacher. It should be practical to conduct and relevant to the syllabus. Even A-Level Biology tutors say that this is a great opportunity to develop your personal interests, while advancing your knowledge of the Biology curriculum.

How can I prepare for the IA?

To prepare for the IA, students should ensure that they understand the material covered in their biology course and should practice writing lab reports. They should also seek feedback from their teachers on their writing skills and their understanding of the research process. IB tutors provide personalized guidance and can help students understand complex topics and achieve higher grades as well.

TutorChase's IB resources , including IB Biology Q&A Revision Notes , are perfect for students who want to get a 7 in their IB Biology exams and also prepare for the internal assessment. They are completely free, cover all topics in depth, also have IB Biology past papers and are structured by topic so you can easily keep track of your progress.

How is the IA graded?

The IA is worth 20% of the final grade for the IB biology course, whether you are studying at Higher or at Standard Level. It is graded by the student’s teacher, who is trained and certified by the International Baccalaureate organization. The report is then sent to a moderator, who will check that the report adheres to the IB guidelines and that the grade awarded is appropriate.

Online Biology tutors emphasise that it is important for students to be familiar with the assessment criteria for the biology internal assessment. These criteria are used to grade the laboratory report and reflective statement, and include aspects such as the quality of the research question, the methodology used, the data analysis, and the conclusion. Students should also make sure that their report is well-written and properly formatted, and that it includes all the required sections.

Recent Changes to the IB Biology IA Guidelines

The IB has recently updated the guidelines for the Biology IA to better reflect the evolving nature of biological research and education. These changes include a greater focus on the application of biological principles to real-world situations, a more structured approach to reflective statements, and updated word count and grading criteria. It is important for students to familiarize themselves with these changes to ensure they meet the new expectations.

Source: IB Biology Subject Guide, pre-May 2025

In summary, the IA in the IB is an opportunity for students to demonstrate their understanding of the biology curriculum, as well as their ability to conduct independent research. It consists of a laboratory report and a reflective statement, and is worth 20% of the final grade for the course. To prepare for the assessment, students should ensure that they understand the material covered in their IB Biology.

Need help from an expert?

The world’s top online tutoring provider trusted by students, parents, and schools globally.

Study and Practice for Free

Trusted by 100,000+ Students Worldwide

Achieve Top Grades in your Exams with our Free Resources.

Practice Questions, Study Notes, and Past Exam Papers for all Subjects!

Need Expert Help?

If you’re looking for assistance with IB Biology, get in touch with the TutorChase team and we’ll be able to provide you with an expert IB Biology tutor . We’ll be there every step of the way!

Professional tutor and Cambridge University researcher

Written by: Charles Whitehouse

Charles scored 45/45 on the International Baccalaureate and has six years' experience tutoring IB and IGCSE students and advising them with their university applications. He studied a double integrated Masters at Magdalen College Oxford and has worked as a research scientist and strategy consultant.

Related Posts

What are the Hardest IB Subjects?

IB Theory of Knowledge: Knowledge Questions Explained

How to Choose Your IB Subjects

Hire a tutor

Please fill out the form and we'll find a tutor for you

• Select your country
• Afghanistan
• Åland Islands
• American Samoa
• Antigua and Barbuda
• Bosnia and Herzegovina
• Bouvet Island
• British Indian Ocean Territory
• Brunei Darussalam
• Burkina Faso
• Cayman Islands
• Central African Republic
• Christmas Island
• Cocos (Keeling) Islands
• Congo, The Democratic Republic of the
• Cook Islands
• Cote D'Ivoire
• Czech Republic
• Dominican Republic
• El Salvador
• Equatorial Guinea
• Falkland Islands (Malvinas)
• Faroe Islands
• French Guiana
• French Polynesia
• French Southern Territories
• Guinea-Bissau
• Heard Island and Mcdonald Islands
• Holy See (Vatican City State)
• Iran, Islamic Republic Of
• Isle of Man
• Korea, Democratic People'S Republic of
• Korea, Republic of
• Lao People'S Democratic Republic
• Libyan Arab Jamahiriya
• Liechtenstein
• Macedonia, The Former Yugoslav Republic of
• Marshall Islands
• Micronesia, Federated States of
• Moldova, Republic of
• Netherlands
• Netherlands Antilles
• New Caledonia
• New Zealand
• Norfolk Island
• Northern Mariana Islands
• Palestinian Territory, Occupied
• Papua New Guinea
• Philippines
• Puerto Rico
• Russian Federation
• Saint Helena
• Saint Kitts and Nevis
• Saint Lucia
• Saint Pierre and Miquelon
• Saint Vincent and the Grenadines
• Sao Tome and Principe
• Saudi Arabia
• Serbia and Montenegro
• Sierra Leone
• Solomon Islands
• South Africa
• South Georgia and the South Sandwich Islands
• Svalbard and Jan Mayen
• Switzerland
• Syrian Arab Republic
• Taiwan, Province of China
• Tanzania, United Republic of
• Timor-Leste
• Trinidad and Tobago
• Turkmenistan
• Turks and Caicos Islands
• United Arab Emirates
• United Kingdom
• United States
• United States Minor Outlying Islands
• Virgin Islands, British
• Virgin Islands, U.S.
• Wallis and Futuna
• Western Sahara

Alternatively contact us via WhatsApp, Phone Call, or Email

IB Biology Internal Assessment Solved: A Guide to Acing Your Biology IA

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 16-page limit, which might seem like a lot to do, but towards the end of the IA you’ll be wishing you had more pages to work with. This guide is aimed to help you ace the IB Biology 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 students 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 do 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 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 increases 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.

Strength vs Weakness

Strengths: In this section I would recommend listing 2-3 strengths and commenting on how they affected the report or experiment.

Weaknesses: In this section I would recommend listing 5-6 weaknesses, and 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.

Further Questions

At the end of the IA, I would recommend including 2-3 further questions which could be explored if you had the opportunity. This improves personal engagement as it shows the marker that you have reflected on the current experiment and thought about what else you could explore.

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.

Best of luck for the Internal Assessment. You’ve got this!!

• Internal Assessment Guides

Recent Posts

What are the IB Internal Assessments (IAs)?

The Complete IB TOK Exhibition Guide

The Complete IB Geography Internal Assessment Guide

Step by Step Guide to Writing Level 7 IB Biology IA

I. introduction, a. brief overview of ib biology ia.

The IB Biology Internal Assessment (IA) is a crucial component of the International Baccalaureate (IB) Biology curriculum . It serves as a substantial piece of written coursework in the form of a scientific report, focusing on a specific experiment. This undertaking provides students with an opportunity to delve into a topic of personal interest within the realm of biology, conduct experiments, analyze data, and communicate their findings effectively.

B. Importance of Achieving a Level 7

Securing a Level 7 in the IB Biology IA is highly coveted for several reasons. Given that the IB curriculum heavily emphasizes coursework, excelling in IAs can significantly impact your overall grade. Attaining a Level 7 demonstrates a deep understanding of scientific concepts, meticulous experimental design, thorough data analysis, and clear communication skills.

II. Understanding the Assessment Criteria

A. criteria breakdown, 1. personal engagement (2 marks).

Personal engagement involves selecting a topic and experiment that holds personal significance or relevance to the student. While topics often align with IB biology content, students have the flexibility to explore areas beyond the curriculum. Examples may include investigating factors affecting plant growth or studying solubility and diffusion patterns of substances. The key is to explain the relevance of the chosen topic to earn these two marks effortlessly.

2. Exploration (6 marks)

The exploration criterion encompasses providing relevant background information and context for the chosen topic. Thorough research is paramount here, incorporating scientific theory, external references, and IB biology concepts. A well-rounded exploration sets the stage for a robust experiment and hypothesis.

3. Analysis (6 marks)

Analysis begins with formulating a clear research question that includes both the independent and dependent variables. Crafting a hypothesis based on research and scientific theory is crucial. Methodology should be detailed yet accessible, with specific equipment measurements and uncertainty. Data collection, processing, and presentation should be meticulous, with multiple trials for reliability. The evaluation phase involves critical thinking, comparing results to the hypothesis, identifying strengths and weaknesses of the experiment, and reflecting on the process.

4. Communication (6 marks)

Effective communication is essential for conveying scientific theories and experiment findings. Proper formatting, labeling of tables and graphs, and adherence to citation and referencing styles (e.g., MLA or APA) are imperative. A well-structured IA with clear communication enhances readability and comprehension.

III. Final thoughts

In the pursuit of crafting a Level 7 IB Biology IA, don’t hesitate to seek reviews and feedback from your teacher—they’re not only there to guide you but also responsible for evaluating your IA. Their insights can provide invaluable direction, helping you refine your ideas, address any shortcomings, and ultimately enhance the quality of your IA. Additionally, it’s crucial to be mindful of common mistakes such as simple grammatical errors and inadequate labeling of equipment in the methodology section. Maintaining a well-structured layout with clear headers facilitates readability and comprehension, ensuring that your IA is easy to navigate for both you and the examiner.

Remember, the IA is not a task to be completed in a single sitting. Starting early and establishing a brief overview allows ample time for successive rounds of review and editing. By adopting an iterative approach, you can refine your experiment design, enhance your data analysis, and polish your communication. Embracing feedback, avoiding common mistakes, and adopting a diligent, iterative approach are key to achieving success in your IB Biology IA.

Select a topic that interests you personally and has relevance to biology. Consider areas covered in your IB biology coursework but don’t hesitate to explore beyond the curriculum if a particular aspect of biology intrigues you.

Follow a structured format with clear headings and subheadings. Ensure proper labeling of tables and graphs, and adhere to citation and referencing guidelines.

Conduct multiple trials for each experiment to enhance reliability. Use appropriate statistical tools to analyze data and draw meaningful conclusions.

Reflect on possible reasons for the discrepancy, considering experimental limitations and external factors. Compare your findings to existing research and scientific theory to provide context.

Effective communication is essential for conveying your experiment’s findings and scientific concepts. Clear formatting, labeling, and referencing contribute to a well-structured and comprehensible IA.

Related Posts

IB Math AASL May 2024 Past Statistics Exam Predictions

In the world of International Baccalaureate (IB) Math, the AASL Math exams hold immense significance, constituting a substantial 80% of…

IB Economics IA: A Step-By-Step Guide

In the realm of IB Economics, the Internal Assessment (IA) stands as a pivotal challenge for students. Beyond the constraints…

7 Essential Tips to Make Your Second Year of IB Easier

Are you a student embarking on your second year of the International Baccalaureate (IB) program? Congratulations on completing the first…