Biology IA
IB Biology IA ideas: 25 guided topics
pick one, then make it yours ↓Twenty-five investigations that work for the Biology IA: plants, enzymes, microbes, fieldwork and databases, with no harm to animals. Open one to see the big idea, how to make it yours, a layout, a sample graph and a plan.
How the IB Biology IA is marked
- 20% of your grade
- About 10 hours
- 3,000 words max
- 24 marks
- Research design 6 marks A focused question and a method that can answer it.
- Data analysis 6 marks Correct processing, with uncertainties carried through.
- Conclusion 6 marks An answer your analysis supports, compared with accepted science.
- Evaluation 6 marks Real weaknesses and realistic improvements.
You may work in a group of up to three, but each student changes a different variable and writes an individual report.
Biology IA ideas to start with
- Capillary rise: can xylem lift a tree by itself?Water climbs a narrow tube with nothing pushing it. So how high does it go, and is that enough for a 100 m tree?
- Does heat-loving mean GC-rich?G-C pairs have three hydrogen bonds, A-T pairs only two. So do microbes that live in hot springs pack in more G and C? Check, and be honest about what you find.
- Build a tree from protein sequencesFossils and anatomy give one family tree; protein sequences give another. Do they agree, and for how long does the 'molecular clock' keep ticking?
- Does mowing change what grows?A lawn looks boring until you count it. How often it is cut decides who survives, and you can measure that.
- Species–area on a school fieldBigger areas hold more species. You'll find out by how much, and fit a number to it.
- Do heat-loving proteins have more charged residues?Enzymes from hot springs survive where yours would unravel. Is there something different on the inside that you can actually count?
All 25 Biology IA topics
- Capillary rise: can xylem lift a tree by itself?●●○
- Does heat-loving mean GC-rich?●●●
- Build a tree from protein sequences●●○
- Does mowing change what grows?●○○
- Species–area on a school field●●○
- Do heat-loving proteins have more charged residues?●●●
- Beetroot and freeze–thaw●○○
- How far does a molecule diffuse in a gel?●○○
- Stomata: sun leaves vs shade leaves●●○
- Transpiration and the air's drying power●●○
- Leaf thickness along a light gradient●○○
- Does metabolic rate really scale with mass^0.75?●○○
- Does maltose slow amylase down?●●○
- Enzyme beads: does size matter?●●○
- Colours of light and photosynthesis●●●
- Practice and reaction time●○○
- Plants that bend toward blue●●○
- Herd immunity in a simulation●○○
- Duckweed: how fast does a population really grow?●○○
- Tea bags: how much soil moisture do decomposers need?●●○
- How often does a mutation change a protein?●●○
- Onion roots: does the mitotic index vary by time?●●○
- Potato cores: does salt or sugar pull more water?●○○
- Corn ear: does counting more kernels change the 3 : 1?●●○
- Natural selection vs chance: will a helpful allele win?●●●
No topic matches. Try fewer words.
IB Biology IA guides
Official course page: the IB Biology pages on ibo.org. Check your teacher's guidance for the criteria that apply to you.
This guide shows how a topic like this is usually approached. It is not an IA. Your question, choices, data, analysis and words must be your own: change something, tell your teacher where the idea came from, and follow your school's rules on outside help.