IB Biology IA Coursework: A Detailed Guide For Students and Parents

 IB Biology IA Coursework: A Detailed Guide with detailed prompts and help: for students and parents.

Your Guide to IB Biology IA Coursework – Table of Contents:

1. Introduction: Why should you listen to my advice on how to get top marks in a IB Biology IA?
2. Overview of the Biology IA – especially for confused parents.
3. A word on planning, preliminary work and communication
4. Common pitfalls – what do I see my students doing wrong time and time again.
5. What can you expect from your teacher….and what you should not expect!
6. Bio IA Criteria 1: Personal Expectation
7. Bio IA Criteria 2: Exploration
8. Bio IA Criteria 3: Analysis
9. Bio IA Criteria 4: Evaluation
10. Bio IA Criteria 5: Communication
11. Receiving feedback and improving your IA
12. Final steps: handing in your IA.
13. Examples of Biology IAs
14. Where can I find Ideas and Resources for my Biology IA?

1. Introduction: Why should you Read this Guide to IB Biology IA Coursework?

I am an IB biology and ESS teacher with 16 years experience teaching the IB qualification in a busy international school. I am a head of science at my school and oversee the delivery of biology, chemistry and physics to a large cohort of students. I also teach across the middle and high school. I am used to preparing students for the IB diploma and there’s nothing more rewarding than seeing students reach their full potential – that may be a grade 4 or a grade 7, it’s all about stretching each student to achieve their very best. Preparation starts in grade 7 when they arrive in my classroom, fresh from primary school. 

I have attended countless IB conferences and workshops – most of these courses were solely about the internal assessment in the IB diploma program. Every year I guide a large group of grade 11 and 12 students through this process and I learn so much from them about how to improve the process each year. I also moderate my student’s work within my department to make sure that our feedback and grading is appropriate. This grading has to accurately reflect the work carried out by the student. Guiding students through this process is difficult and it can take years to become really confident with the entire process. My many years experience working on a daily basis with IB students puts me in a strong position to be able to guide you through this process. If you have any additional comments or questions don’t hesitate to email me at info@holatutor.com

2. Overview of the Biology IA – especially for confused parents.

What is the point of IA (Internal assessment) in science? I think the IB has a duty to train students for the challenges of university life and, ultimately, to be effective scientists. How effective it is at doing that is certainly debatable. But there is some evidence that it is trying. The group IV project, with its multidisciplinary groups of students, is one example of the IB trying to recreate real experiences that professional scientists may encounter. The IA attempts to do this by giving students freedom to carry out a study into any area of biology. Many different skills are tested from planning and project organisation to data collection and analysis. All very applicable to later challenges in university and beyond. So in short the IB biology IA is a great chance for students to show their capacities in both academic and life skills. It’s no walk in the park and it’s a worthwhile rigorous test of your science abilities.

preparing of chemicals.
The IB IA is excellent training for your university academic career.

What is ‘Internal Assessment’ ? All IB subjects have a ‘coursework’ section. This is known as ‘Internal Assessment’ in the IB world and work is graded by the subject teacher. Samples of the class work are then sent to the IB for moderation. Following this moderation the IB may decide to raise or lower the grade of that particular class. 

How much is the Biology IB IA grade worth? In IB Biology (and all IB sciences) the grade is worth 20%. This means the exam is worth 80%  – this gives you an idea of where you should be placing your priorities in the long term. The IA is important, but nowhere near as important as the final exams. Bear that in mind. 

Is there any difference between SL and HL Bio for the IA? The requirements for the IB are identical for both SL and HL students. 

How long should I spend on my Bio IA? The official time allocation is 10 hours for both SL and HL. In my experience many students spend much longer than this on their IA projects. It’s important to try to get the IA completed within the deadlines imposed by your teacher to avoid a clash with other IB subjects. 

What are the criteria and where do I find them? If you look further down in this article you will find detailed reference to each criteria with plenty of help, advice and guidance. 

Overview: How the Grading Works in Biology and all IB Science IAs:

IB Sciences IA Overview

3. A word on Planning, Preliminary Work and Communication

Planning, preliminar work and communication – all major challenges for most human beings. IB students are no exception and it’s these areas that make or break a decent IB Biology IA. Here’s my tips on getting these crucial areas right:

Planning: Make sure you know your timeline for your IB Biology IA: Your teacher should provide you with a clear deadline – one for the first draft and a second for the final draft. If you don’t have these, ask for them.  Plan how long it will take you to set up your investigation and work your way backwards. Add in time for mistakes and setbacks – this happens to nearly all students. See the next section on common pitfalls.

Preliminary Work: Preliminary work is a great way to show your planning skills and will give you invaluable indications as to whether your investigation will actually work or not. Spend a day or two carrying out a ‘dry run’ or practise of your experiment.

Preliminary Work: A Step That Easily Boosts Your IA grade

Consider: Does your equipment work as you expected? How much of each material will you need? Is there enough of this material in the lab – you may need to speak to the lab technician to order more. Are the results as expected? How long did it take you to carry out one trial? Do you need to add more trials or actually reduce the amount of trials you intend to complete?  Did you have any problems sourcing a particular chemical or material? Can you use this data to inform your prediction?

If your teacher doesn’t give you time to do this during class you should try to find an hour or two after school or during free periods/lunch time to quickly set up your experiment and let it run. The time investment here will pay you back immensely as you start your experiment for real. The takeaway: it’s easy to ignore preliminary work but you do so at your peril. 

setting up preliminary work
Get some preliminary work done and see if your ideas actually work.!

Communication: Substandard communication skills often end up affecting IA scores. Elements of your communication skills are assessed in the grading criteria ‘Personal Engagement’ but mainly in the ‘Communication’ section. Check your email and respond to your teacher or the lab technician. Seek help when you need it. Otherwise you risk problems with equipment and materials running out and deadlines being missed. Think of the Biology IA being one of your biggest all round tests as a student. It’s not just about writing the report but also acting in a professional way with those around you and making the most of this support. So please answer those emails and keep on top of deadlines. If you have any problems, let your teacher know as soon as they arise. 

4. Common pitfalls – what do I see my students doing wrong time and time again?  

Pitfall1: Selecting a flawed research question

 Time for a chat about that research question. Remember that your research question sets the field for your study. If your research question is poor, it’s very likely that your investigation will follow suit.  You’ll need to make sure the research question is well crafted and focused. It must actually ask a question that makes sense. The reason for asking this question must be obvious.

If you construct a bad research question….be ready to face the implications.

Recently I had a student comparing the time it took for raw fruit and canned fruit to go bad. He had barely any idea how he could measure this – I helped him with some ideas but I was still uneasy about WHY he was asking this question – who cares if canned pineapple will go off faster than fresh pineapple? Really – who cares?!! Actually some chefs may care and the affect of fruit storage on decomposition rates may well be important in some catering industries. You have to be able to substantiate your question.  I asked him to explain the reasons, but he couldn’t. Despite my reservations he stuck with his confusing original research question, which lead to confusing analysis and evaluation sections and came out with a mediocre mark. 

Pitfall2: Selecting too many IVs

 If in doubt stick to one independent variable, or two maximum. Adding more will make your task overly complicated during the analysis and evaluation stage. Are you really able to separate out those variables? If you are confident you better have a water tight method that ensures that your variables are able to be dealt with separately. If i am really honest I feel this beyond most students. So please stick with one or two independent variables. Studies that focus on one or two variables are more than able to gain full marks. 

Pitfall3: Selecting IV/DV that aren’t quantifiable/easily converted to numbers

Ideally both you independent and dependent variables should be NUMBERS – quantitative data. If you pick a topic and a research question where one of the variables is WORDS – qualitative data – then you should try to tweak your plan so that both are quantitative data.

Scientists Get Excited When They Use Numbers For Good Reason

Why do scientists get excited about numbers? One big reason is when it comes to data analysis you will be able to construct scatter plot and not simple bar charts. You will have far more freedom when it comes to analysing your data too. So when it comes to variables: try to make sure both are quantitative  – i.e they can be expressed as numbers, not words. Here’s a simple example: A student is looking at a simple study involving temperature. They plan to have seeds growing in HOT, WARM, COOL, COLD and FROZEN conditions. This is a very simple study and maybe too simple, but they should certainly change those numbers to specific temperature references, for example 90ºC, 60ºC, 20ºC, 10ºC and -8ºC.

Pitfall4: No preliminary work

As mentioned in this article here:  Preliminary work is very important. Don’t want to do it? OK fine. I always have a few students who for whatever reason cannot get the time to carry this out. Invariably it will be these students who, halfway through their study, realise they must start again with more finely tuned intervals of the independent variable. Or they run out of materials half way through because they didn’t realise that they actually need 50ml of H2O2 per trial and not 20ml as planned. They failed to let me or the lab technician know. They may also spend the first week of experimental time fiddling with equipment before deciding that it doesn’t work. All this could and should be sorted out during the preliminary stage of your investigation. Ask your teacher to provide time for this if they don’t offer it to you. They won’t be able to give you much but possibly a lesson or two and you can eek out more time at lunchtime/after school if you really need it. 

Pitfall5Collection of data that is patchy and/or doesn’t apply itself to advanced data analysis.

If you plan effectively and spend an afternoon completing your preliminary work, you should collect plenty of data that lends itself well to analysis and processing. Your plan should enable you to fill a large table of data with detailed results that are 100% relevant to your research question. The test here is to look at your preliminary result data – is it patchy? Can you easily scale your efforts to make  ‘n’ (sample size)  greater than 70? If so then proceed. If not then you will need to return to your plan, and adapt. You may also need to check in with your teacher for advice and guidance.  

Pitfall6: Opting for a ‘research project’ with no data collection.

This is a tricky one.The IB permits research projects where students carry out research into existing databases, ‘data mining’ as it’s often called. Each year I have one student who is determined to do their IA as a research project. No experiments, no collecting original data. They usually end up exploring online data resources such as some of the WHO databases or GenBank. They may find some data for one of their variables, but finding data for the second variable proves very difficult.

Choosing a ‘Research Only’ Investigation for your IA – Risky, Risky, Very Very Risky.

I remember one student who decided, against my advice, to carry out a research project. He was searching for information on the incidences of influenza in Europe, including very specific regions of specific countries. He couldn’t find any reliable, consistent data on this and spent months ringing universities, trawling through websites. He couldn’t rewind as he hadn’t carried out his preliminary work and hadn’t been able to preempt these issues. I did my best to help, but there is a limit to the time I can devote to chasing up requested results from university departments who never reply. It was very frustrating and the student handed in a mediocre report.  These online databases are great. There’s no doubt that they are incredible resources, but are often too technical for most IB students to work with – most are aimed at the biologist with a PhD and professional experience. In my experience I would recommend that students design their own investigation and collect their own data. In short: be very, very wary with IB biology IA research only projects. My advice is don’t go there.  

Pitfall7: Assuming that the chemical/materials/equipment cupboard is an ‘Aladdin’s cave’ of Magic Resources. 

This is a good one. Many students seem to assume that all materials known to mankind are stored in the magic storage cupboard and can be replenished instantly. This isn’t the case – you really do have to check if your school has what you need and in what quantities. Let the teacher/lab technician know how much you’re going to need. Order any low supplies in advance. In short – reply on your preliminary work to guide in the quantities you will need, then let the science department know with plenty of time so that you will have all the materials you need. 

Pitfall8: Poor communication

Throughout the process it’s really important to let your teacher know if you encounter any problems. Don’t just soldier on or stop without letting someone know that you need help. Time is usually very tight – you only have around one week for data collection – I advise my students to complete their data collection in less than 3-4 lessons to allow time afterwards for writing up their report and analysing the results. Use email, or stop by the lab when you have time to seek this support. Leave a note on your teacher’s desk  – they will get back to you. At your workstation have an area where you can write down notes and qualitative (word) data. As you hit issues and have questions note them down. You can send these to your teacher, or they might even read them as they check over each workstation at the end of the day. 

5. What You Can Expect From Your Teacher….and What You Shouldn’t expect!

You can expect your teacher to:

  • introduce and outline the requirements of the course.
  • Let you know what equipment/materials are available.
  • Give you time (10h) in class to carry out your IA project.
  • Give you a space to work in your laboratory – ideally ‘fenced off’ and labelled as your space.
  • Put you in contact with the lab technician to help you source and order the materials you need.
  • Give you official written/and oral feedback after the first draft – I like to do this as a 1:1 meeting where I go through each area of the first draft, relating the students’ work to the IB grading criteria.
  • Give you informal help, guidance and assistance when needed as you work through your project and face challenges.

You shouldn’t expect your teacher (or anyone else!) to:

  • Write any part of your report for you. This is taken very seriously by the IB, all work must be your own.
  • Offer regular and lengthy written feedback on the progress of your IA – teachers are not really allowed to do this. We can provide quick help and assistance as you progress through the process. The only time we can officially provide written feedback is for your first draft.
  • Offer feedback on your final draft – once that is handed in your task is complete !


6. Biology IA Criteria 1: Personal Engagement

You should know:  Personal Engagement is all about assessing your motivation, originality and independent thinking. 

As an IB Biology teacher and IA supervisor what are the general questions that I am asking myself when grading Personal Engagement?
  • Did the student need regular intervention to solve simple/easy to resolve issues?
  • Does the student’s plan involve original ideas?
  • Does the student justify their study? 

Personal Engagement: Give me some Prompts to help me check my progress:

Evidence of personal engagement/Evidence of independent thinking, initiative and insight/Justify your reasons for choosing this topic/ Can you demonstrate personal input and initiative in the design, implementation and presentation of the investigation?

IB Biology IA Criteria: Personal Engagement


7. Bio IA Criteria 2: Exploration

You should know: Exploration looks at the details of your plan for your IA. It is the most important stage and the stage that many students often neglect. You need to collect data that provides clear evidence to support your research question.  How can you write a good conclusion if your raw data is incoherent, patchy or just, simply wrong? A well thought out exploration stage will set you up for success and preliminary work will help you make sure you get this stage correct. 

boy in field
Pick a research question on a topic you actually find interesting.

As an IB Biology teacher and IA supervisor what are the general questions that I am asking myself when grading Exploration? 

  • How well written and focused is the research question?
  • Does the background information support all the variables in the research question?
  • Are the variables well defined and do the intervals make sense?
  • Has the student thought about ethical, environmental and safety issues?
  • Has the student carried out preliminary work and thought about how the results may look?


How To Write a Great Research Question For IB Sciences


Research Question Examples:


Can you find the following elements in your Research Question? Is it focused?


What Headings Should you consider using in the Exploration Section? Title, Research Question , Hypothesis, Background Information, Variables, Apparatus, Chemicals and Materials, Safety, Ethical and Environmental Issues, Preliminary work, Prediction Graph, Method.

Give me some Prompts to help me check my progress for the Exploration Section:

Clear title/relevant research question (include IV & DV)/research question supported by referenced background information/Define IV (state clearly the units, uncertainty and minimum five intervals) & DV (quantitative with units and uncertainties)/ For each control variable – create a table – identify the control variable and say why and how will you control it /State how you have organized repeats and runs – min 5×5 rule (more for the individual project)/hypothesis must be explained with science/apparatus list with sizes, units and uncertainty/why did you chose that apparatus?/chemicals & materials – amounts units and concentrations/Safety, ethical and environmental issues – for example: if you use any living organism (including humans – consent forms) you must discuss how you ensured their well-being. /Did you carry out any preliminary work ?– give details/Clear step by step method, using passive voice or imperative – ie: ‘50ml of sucrose solution were measured’ or ‘Measure 50ml of sucrose solution’ notI measured 50ml of sucrose solution’. /Prediction graph – It’s often a good idea to draw a graph that predicts how you expect your final graph to look/Is it possible to see variables being controlled in your method? 


IB Biology IA Criteria: Exploration


8. Bio IA Criteria 3: Analysis

You should know: The analysis section covers two main sections. First dealing with your raw data and then processed data. By this point in your report you are depending on your collected data to work with. This is why the exploration section is so important – it’s the exploration session that provides this data, so it’s now, in your data collection, that the quality of your planning will show through. You need to focus on the details, so make sure your uncertainties are covered, your tables and graphs need to be well presented with sufficient, coherent data that actually makes sense. 

Success in your IB Biology IA Depends on Sound Statistical Analysis

Work on making your tables and graphs as easy to read as possible  – you don’t have to suspend the level of rigour in the graphs to do this. One area that students often find challenging is tackling higher level analysis – such as the T-TEST or CHI-SQUARED. Students must judge which statistical test to do depending on the type of results they have, asking for teacher guidance at this point is not a bad idea. Error bars are always fun – generating standard deviation values and using these as your error bars is (as of April 2020) only really possible in excel/advanced spreadsheet programs. Except for complex work arounds, google sheets cannot add custom error bars. Using google sheets for most of your report is fine – I am a big fan of the program, but for custom error bars you’re still best shifting over to a more advanced program – such as microsoft excel. 

As an IB Biology teacher and IA supervisor what are the general questions that I am asking myself when grading Analysis section? 

  • Is there sufficient data, across relevant and sufficient ranges to answer the research question? 
  • Are the tables and graphs appropriate for this study? 
  • How easy is it to interpret the tables and graphs? 
  • Has the student used higher level statistical analysis and how effective is it? 
  • What trends are apparent and has the student correctly identified these trends? 

What Headings Should You Consider Using in the Analysis Section? 

Possible headings: Data Trends, Conclusion (Claim, Evidence, Reasoning) , Error in Experimental Method, Reliability of Data, Sources of Random and Systematic Error.

Give me some Prompts to help me check my progress for the Analysis Section:

Points to consider: Identify and explain trends in your data/Describe and justify a clear conclusion that is relevant to your research question and supported by your data/justify your conclusion using science – referring to background information could be useful here/references in footnotes and in a reference section at the end – using ‘science style’ for a guide conduct a google search for ‘sciencemag referencing style/Experimental method: in table format – identify meaningful sources of error and suggest specific and detailed improvements for these errors/Reliability of data: in table format discuss the quality, reliability and limitations of the data collected/discuss systematic and random errors in your design and data collection (see appendix in this document for an explanation).

IB Biology IA Criteria: Analysis

Personal Engagement


9. Bio IA Criteria 4: Evaluation

You should know: The evaluation is all about answering your research question. The whole point of your study is to gather evidence to answer the research question – so make sure your evaluation sets out to do this. Your main source of evidence will be your processed data and the graphs produced. 

As an IB Biology teacher and IA supervisor what are the general questions that I am asking myself when grading Evaluation section?

  • Does the student answer the research question, ideally succinctly in the first paragraph?
  • Does the student correctly identify the main trends in their data analysis? 
  • Does the student explain the trends using existing (and referenced) scientific knowledge?
  • Does the student attempt to identify the strengths and weaknesses of the study?
  • Does the student identify non trivial improvements? 
  • Does the student discuss the reliability(limitations of their data?
  • Does the student suggest extensions of their investigation? 

What Headings Should you consider using in the Evaluation Section? 

Possible headings: Data Trends, Conclusion (Claim, Evidence, Reasoning) , Error in Experimental Method, Reliability of Data, Sources of Random and Systematic Error. Extensions of the Investigation. 

Give me some Prompts to help me check my progress for the Evaluation Section:

Points to consider: Identify and explain trends in your data/Describe and justify a clear conclusion that is relevant to your research question and supported by your data/justify your conclusion using science – referring to background information could be useful here/references in footnotes and in a reference section at the end – using ‘science style’ for a guide conduct a google search for ‘sciencemag referencing style/Experimental method: in table format – identify meaningful sources of error and suggest specific and detailed improvements for these errors/Reliability of data: in table format discuss the quality, reliability and limitations of the data collected/discuss systematic and random errors in your design and data collection. 

IB Biology IA Criteria: Evaluation


10. Bio IA Criteria 5: Communication

You should know: The communication grade is when the teacher or moderator takes a step back and asks the question ‘How easy was it to understand and follow this report?’ 

As an IB Biology teacher and IA supervisor what are the key questions that I am asking myself when grading the Communication section? 

  • How easy was it to follow the report from beginning to end? 
  • Did I have to keep going back to check on details to understand a particular section?
  • Does any lack of clarity affect the understanding of the report? 
  • Is the report well structured with informative subheadings?
  • Have formatting tools used correctly to aid the reader in understanding the report? 
  • Is the writing relevant to the topic or does it meander off topic at times? 
  • Is the language pitched at an IB Biology level? (or is it too simple or indecipherable at times?)
  • Is an appropriate referencing system used consistently throughout the report?   
Communicate your ideas and discoveries in the most succinct and accurate way.

Give me some Prompts to help me check my progress for the Communication Section:

Points to consider: Clear presentation of your report with distinct sections with clear titles – it’s better to include more headings and sections than less/Is your report coherent, easy to understand and logical – with no errors that make it difficult to work out what you did and what you found out?/ Subject specific terminology – are you using IB level terms in the correct way?/Have you presented your raw and processed data correctly?- following the correct conventions for uncertainties, laying out example calculations, displaying error bars, keys in graphs etc/Have you checked your report is an appropriate length (6-12 pages for individual project ) and contains references  footnotes and page numbering and appendices when needed.


11. Receiving feedback and improving your IA

Your teacher will provide you with formal feedback on your first draft. I like to sit with each of my students and go through each point with them. It’s important that you look back to the criteria and see how you’re doing in each area. Your teacher should give you guidance on how to improve your first draft for the final draft. Bare in mind that your teacher’s improvements are highly unlikely to raise your grade to full marks. But they should help you improve your grade – if you mange to apply them correctly. Don’t forget you can still check in with your teacher for verbal guidance on any areas that you need help on – many of my students do this and it makes a big difference in the quality of their report. 

12. Final steps: handing in your IA

The IB has some strict rules on the format of your final report. You must follow these carefully , but they are all fairly reasonable and logical: 


  • Maximum 6-12 pages
  • All work clearly referenced and coherent– ‘science style’ recommended, MLA fine.
  • Spell-checked
  • Numbered pages,
  • Mainly portrait orientation, although tables and graphs can be landscape if required.

Personal details:

  • Your name, candidate number or school name/logo should ONLY be found in the file name of the file, not in your document; the electronic cover sheet completed on IBIS contains all the necessary information
  • The electronic essay file name only should be labelled with your name, candidate number, subject and component, for school identification purposes.

File name:

  • Use the following format including your first and second names, candidate number, subject and component:

Example: jameswatsonhty654BiologyIA

File type:

All final drafts should be emailed as PDF files – max size 50MB

Sending your file:

If you’re one of my students: email the final draft of your essay, in PDF format, to both my Urkund email address and copy (cc) to my school email address by 17.00 on the deadline date. Check with your teacher to find out how they would like you to send them your final report. 

Worth remembering:

  • Once you have sent your final version you cannot make any further changes.
  • Your teacher may accept final drafts early  if so and you have it done and checked, and double checked then send it in early.
  • IAs will not be accepted by the IB  if they do not meet the requirements listed above.
  • To help me assess Personal Engagement I ask my students to fill in the  ‘assessing personal engagement’ form. Your teacher may do something similar. 

13. Examples of Biology IAs

Your teacher should be able to provide you with some examples of Biology IAs. I make a collection available to my students prior to starting the IA and we look at them and analyse why they got the scores they did. Ask your teacher to provide you with such a collection or a search of the internet, especially Reddit can help. Please DO NOT be tempted to copy or plagiarise previous IAs – most schools worth their salt pass final IA through a rigorous plagiarism prevention program (my school uses URKUND) You will be found out and the consequences are serious indeed. 

The website: ‘Biology for Life’ is an excellent resource. It has some excellent resources for the IA including some annotated sample IAs. Worth checking out. 

14. Where to find ideas and resources for your Biology IA?

Like most tasks – starting can be the hardest part. And finding a valid idea that works within all the restrictions and parameters can be a real challenge. Here’s a list of places I recommend students visit to find resources and ideas. The links here have consistently inspired excellent projects. Please bear in mind that you shouldn’t just copy these ideas but take their methods and concepts and adapt them to your own study:

IB IA Description and Assessment Criteria: The Official IB Grading Criteria for the IA sciences.

IB BIOLOGY IA IDEAS: Large collections

1. IB Bio Internal Assessment. Biology for Life: this is an amazing website run by a fellow biology teacher. Plenty of help and ideas on this website.

2. Senior Biology EEI Ideas

3. Science And Plants for Schools has lots of botanical investigations and ideas

4. Practical Biology brings together lots of different biology practicals for all ages of student

5. Vernier data loggers can be used in individual investigations and vernier publishes ideas and details of how they can be used for biology experiments.

6Action potentials and movement in plants

7.  Mr G’s science site  (Lots of ideas here)

IB BIOLOGY IA IDEAS: On Specific Topics

1. Working with petri dishes

2. Soil Microfauna – Berlese Funnel/soil microfauna

3. Paper detailing simple techniques with enzymes.

4. ‘Easy enzyme experiments anyone can do

IB BIOLOGY IA ‘STARTER IDEAS’: Use these to find an interesting starting point

Topic 1 – Cell Biology

  • Factors affecting Osmosis (ex. Investigating the effect of time (or?) on the plasmolysis on potatoes)
  • How will the weight vary between the sweet potatoes and potatoes when placing each sample in different concentration solutions?
  • Distribution of cell size using microscope in plant tissues
  • Outer vs inner cell size on onion leaf
  • Outer vs inner cell osmolarity
  • Number of stomata on top and bottom of leaf
  • Food tests
  • Amount of starch, relative color change, quantified with colorimeter
  • Specialized cells
  • Root hair cells – at what age are they most visible?
  • Mitosis in root tips
  • Pollen tubes
  • Surface area to volume ratio
  • Energy value of different types of foods
  • Different sizes of bacterial cells (different places, etc)

Topic 2 – Molecular Biology

  • Properties of water
  • Water as a habitat
  • Surface tension
  • Respiration
  • Yeast
  • Germinating seeds
  • Fermentation
  • What affects the amount of CO2 produced by the reaction of yeast?
  • Photosynthesis
  • Pigments – at different ages/different species
  • Rate of product production in different enzymes
  • Is there a change (decrease / increase) in oxygen (O2) production (number of bubbles) of water weed with changing light intensities?
  •  Directly/indirectly measured
  • Light colors
  • Types of light (natural, LED, etc)
  • UV light on duckweed
  • Acid on germination
  • How does different factors, (temp, pH, chemical composition of soil etc) affect soils
  • To investigate how time affects the amount of water lost by potatoes, by measuring at how much water a cylinder cut from a potato (4cm in length) can take up after various amounts of time
  • Enzymes
  • Catalase
  • Lactase/milk data logging
  • Effect of temperature on casein
  • To determine the maximum rate of reaction of peroxidase enzyme in a suspension of yeast cells (Saccharomyces cerevisiae).
  • Pectinase
  • To investigate the effect of increasing temperature on the activity of the enzyme pectinase, that will be allowed to act on equal sized pieces of apples and the volume of juice compared.
  • To determine if the there is a relationship between the primary structure of barley (Hordeum vulgare) amylases and the effect of pH buffers (ranging from pH 3 – pH 11) on them.

Topic 4 – Ecology

  • Diversity indices
  • To compare the number of prickles per leaf on branches of Ilex aquifolium coming from the east side and west side of a holly tree as an indication of leaf adaptations.
  • Leaf miners
  • (T test/Chi square)
  • Populations size/Lincoln index
  • Measuring the relative density of invertebrates along a line transect and associated abiotic factors
  • Internodes
  • How does sun exposure affect above ground dry biomass of grass?
  • To model the effect of adjusting the light level on predation using a simulation of natural selection on peppered moths (Biston betularia) with human predators.
  • Compare height/size of plant here to there
  • Ex. Plantago
  • Pond studies
  • Stratification/diversity
  • Count and classify species
  • Oxygen concentration
  • Light intensity
  • Co2 levels
  • Fish behaviour
  • Insects/Invertebrates


Topic 6 – Human physiology

  • Strength tests of tissue types
  • Meat/bones/hair (tensile strength)
  • Digestion enzymes
  • Amylase
  • Breathing rate
  • Heart rate
  • Ruler drop
  • Is there a relationship between Countries’ Human Development Index (HDI) level and the incidence of tuberculosis?


 Topic 9 – Plants

  • Fruit ripening (ex. How do two different methods of fruit ripening affect the metabolism of starch to glucose in nectarines over 7 days?)
  • A study on the effect of water on the germination and growth of eucalyptus
  • To measure tannin levels in Piper leaves in areas of different amounts of sunlight in the Tambopata jungle. Can be adapted for other ecosystems.
  • Transpiration Rate: Surface area, Species, Upper vs lower leaf, effect of Vaseline, Wind, Temp

Option Topic A: Neurology and Behaviour

  • An examination of the effect of temperature/light/stimulus on the rate of movement in maggot/woodlice (Pill bugs) 


Are you also writing your extended essay in a science subject?

You’ll need a helpful guide outlining how to plan your investigation and deal with the unique extended essay criteria. Be sure to check out this link:  Holatutor guide to writing 11 tips for success in your IB Science Extended Essay  It’s full of helpful tips and insights that will make sure your essay gets the highest grade.