IB Biology IA examples

Starting from the May 2025 session, the Biology IA requirements have changed. We created a couple of exemplars to show you how the new IA should look like. It's OK to refer to the old Biology IA exemplars (since the new IA is quite similar) for inspiration/ideas, but make sure to follow the new requirements.

IB Biology IA examples

Not sure what to search for? You can always look through our example Internal Assessments below for inspiration.

All Biology IA Examples

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Filter exemplars

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IA

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TOK

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Subject

Grade

Level

Session

What is the effect of the socio-economic development of European countries, as measured by the HDI, on the mortality rate from hypertensive heart disease within the older population (50+)?

What is the effect of increasing iron (III) chloride concentration (0 mg/L, 2mg/L, 4mg/L, 6mg/L, 8mg/L, 10mg/L) on the growth of duckweed (Lemna minor) in terms of change in number of leaves over 5 days?

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How does the presence of earthworms influence the growth of stem in length [cm] of monocots (Avena sativa) and dicots (Phaseolus vulgaris) as measured by the mean height of the stem through 25 days?

What is the effect of the concentration (0%, 20%, 40%, 60%, 80%, 100%) of tea tree (Melaleuca alternifolia) oil on the growth of bacteria (non-pathogenic DH5- Alpha Escherichia coli) measured in the diameter of the inhibition zone around the paper disc?

How do altering salicylic acid concentrations (0.0%, 0.5%, 1.0%, 1.5%, 2.0%) affect the germination of Capsicum annuum longum seeds measuring the radicle length (mm) of the sprouts over 7 days?

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How does the concentration of 50ml of ethanol solution (15%, 30%, 45%, 60%, 75%) influence the cell membrane permeability of beetroot, measured by the absorption transmission of light (Au) using a colorimeter, for 10 minutes?

How do different temperatures (15.0℃, 20.0℃, 25.0℃, 30.0℃, 35.0℃ ± 0.5℃) affect the lactase enzymatic activity in milk determined by the glucose levels (mmol/L) presented after its incubation period (60 minutes) measured using a blood glucose meter?

How do different concentrations (0%, 20%, 40%, 60%, 80%, 100%) of tea tree (Melaleuca alternifolia) oil affect the growth of bacteria (non-pathogenic DH5-Alpha Escherichia coli) measured in the diameter of the inhibition zone around the paper disc?

How do varying concentrations (0.0,0.1,0.2,0.3,0.4,0.5mol/dm3) of sucrose (C12H22O11) affect the cell respiration rate in yeast (Saccharomyces cerevisiae) by measuring the volume of carbon dioxide (CO2) gas released after yeast activation using a gas syringe over a period of 10 minutes?

How will differences in soluble fiber concentrations, ranging from 0% to 2%, affect the rate of hydrolysis of starch in 10 minutes, using a pancreatic amylase enzyme?

What is the effect of the volume of copper sulphate solution (0 cm3, 2 cm3, 4 cm3, 6 cm3, 8 cm3) added on the rate of hydrogen peroxide decomposition catalysed by catalase as measured by the height of the oxygen bubbles produced (mm) in 15 minutes?

What is the effect of different KCl percentage concentrations (0.0, 0.5, 1.0, 1.5, 2.0, 2.5) on the germination rate of Triticum Aestivum.

How does changing the concentration of coffee solutions (0.000%-1.000%) affect the hydrolysis of egg albumin by using the stomach enzyme, pepsin, after a period of 20 minutes?

What is the effect of increasing Fe (III) concentration (2mg/L, 4mg/L, 6mg/L, 8mg/L, 10mg/L) on the growth of Duckweed (Lemna minor) in terms of change in number of leaves over 5 days?

How does the concentration of lactose, altered by diluting whole milk with water at five different concentrations (20%, 40%, 60%, 80%, 100%), affect the rate of lactase activity, measured by how quickly glucose is produced?

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How do varying concentrations of Aloe vera gel (10%, 20%, 30%, 40%, 50%) in a pH balanced solution (pH 4) affect the percentage dehydration of Red Delicious apples (Malus domestica) measured by the change in mass (g) after a period of 7 days?

How do varying concentrations of hydrogen peroxide (0%, 1.5%, 3.0%, 4.5%, 6.0%, 7.5%) affect the radicle length (mm) of Vigna radiata during its one-hour imbibition (pre-germinative seed soaking) before seed germination over a time period of 72 hours?

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What is the correlation between the Human Development Index (HDI) and the prevalence rate of type 2 diabetes (measured in the number of prevalence by 100 people) in countries worldwide?

How do altering salicylic acid concentrations (0.0%, 0.5%, 1.0%, 1.5%, 2.0%) affect the germination of Capsicum annuum longum seeds measuring the radicle length (mm) of the sprouts of over 7 days?

What is the correlation between Human Development Index and case-fatality rate due to breast cancer per 100,000 people in 2020 among very high and highly developed European countries in female populations aged 45 or more?

What is the effect of the Aspergillus species present (A. luchuensis and A. luchuensis mut. kawachii) and the concertation of koji used (0.0%, 10.0%, 20.0%, 30.0%, 40.0%) on the process of amazake fermentation measured by the change in pH over the period 6 hours at a temperature of 60.0°C?

How does increasing the concentration of H2O2 (0%, 1%, 1.5%, 2%, 2.5% and 3%) affect the germination rate (%) of Vigna radiata (mung beans) and the radicle length of each seed measured in mm over 48 hours?

What is the correlation between the human development index (HDI) of 30 countries in Europe and the incidence and mortality rates of lung cancer (measured as incidence and mortality rate per 100,000)?

How does the use of germination stimulators; mineral “Seedboodster Plus” and hummus-based “Brunatne BioZloto” affect germination capacity (GC), germination speed (GS) and mean germination time (MGT) of fresh and old seeds of alfalfa (Medicago sativa)?

How is the daily growth rate of Lemna minor populations influenced by increases in phosphorus concentrations within closed aquatic systems?

To what extent do the different acidity levels of acidic, neutral, and alkaline solutions on the pH scale affect the coloration of teeth?

Investigating the effects of using different types of tea on the number of successful germinations of lentils (Lens culinaris)

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How does the rate of Saccharomyces cerevisiae fermentation, measured by volume of CO2 produced (in cm3) over a period of time (5 minutes), change with type of sugar (glucose, fructose, lactose, maltose, sucrose)?

How do the emissions in metric tons of a country affect the incidence rate of non-communicable diseases (Lung Cancer and Chronic Obstructive Pulmonary Disease) per 100,000 people in Europe?

How does increasing the potassium concentration in Green Tea (0, 20, 40, 60, 80, 100 mg/ ) affect the𝑑𝑚3 average shoot growth rate of Vigna radiata, over 120 hours?

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How do different brands of grain bars found within the weight-loss section of a grocery store, compare in their experimental energy content?

How does rate of respiration of different types of seeds (Vigna radiata, Vigna unguiculata, Glycine max, Phaseolus vulgaris, Sesamum indicum) over 4 hours differ investigated by measuring colour of hydrogencarbonate indicator absorbance value (Abs ± 0.001) using spectrophotometer set at 431.0nm?

What is the correlation between HDI and the mortality rate due to hypertension per 100,000 of the population for countries worldwide?

What is the effect of different local fertilisers on the rate of the eutrophication process?

How does the increase of sucrose concentration, ranging from 0% to 20%, affect the rate of fermentation in Saccharomyces Cerevisiae, as measured by the Carbon dioxide concentration produced in 5 minutes?

To what extent does the activity of the enzyme catalase vary in Cucumis sativus (cucumber), Spinacia oleracea (spinach), Solanum tuberosum (potato), Musa acuminata (banana) and Ananas comosus (pineapple) at a temperature of 37 degrees celsius, measured by volume of oxygen released?

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Fast track your coursework with mark schemes moderated by IB examiners. Upgrade now

Want to get full marks for your IA? Allow us to review it for you

Fast track your coursework with mark schemes moderated by IB examiners. Upgrade now

Want to get full marks for your IA? Allow us to review it for you

Fast track your coursework with mark schemes moderated by IB examiners. Upgrade now