The best topics for your biology internal assessment

It’s that time of year again, and the Biology Internal Assessments (IA) are necessary to complete your IB classes. However, the only downside is that it can be a bit of a hassle to spark your creative mind and generate some unique ideas.

To help you with this decision, we have created a comprehensive list of Internal Biology Assessments to help you finalize your decision and officially complete your IB classes. Want to know about them? Read below.

Our 8 best ideas:


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1.The effects of salt on seed germination

The first inspiring internal assessment in biology to consider is the effects of salt on seed germination.

Halophytes, also known as salt-tolerant plants, can grow in soil or water with high salinity, while normal plants do not. This internal evaluation wants to show the difference in germination between halophytes and normal seeds.

  • Experiment requirements – You will need to conduct a seed germination experiment with both halophytes and normal seeds. With this, you will want to keep adding solutions such as NaCI. As you do this, you will need to observe the germination process.
  • Independent variables – Halophytic (salt-loving) seeds versus seeds from normal (non-salt-loving) plants.
  • Dependent variables – Overall germination success and germination rate.

2. Reducing the potential for deterioration of plants

Vegetables decompose due to damage caused by small microorganisms such as bacteria and mould, but how can we reduce this? In this internal assessment, you will investigate how different environments increase or decrease the rate of decomposition.

  • Experiment requirements – Create several environments that have different temperatures, accessibility to water and oxygen, and then measure the rate of decay.
  • Independent variables – Temperature, water, oxygen
  • Dependent variables – The rate of decomposition. This can be measured by mass, temperature change or pH levels. or pH levels.

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3.Colour vision assessment

The following internal assessment can be simple if you can get enough people together to do the test. To do this, you will use an online or book-based colour vision test and measure which factors affect colour blindness.

  • Experiment requirements – the experimental equipment will vary depending on whether you choose the online or offline route. To learn more about how to conduct a colour blindness test, I recommend you take a look at this post.
  • Independent variables – Tiredness, age, gender, eye colour
  • Dependent variables – Accuracy of the eye test

4.Fruit ripening speed and vitamin C content

As in the previous experiment on decomposition, for this internal assessment you will measure the rate of ripening of the fruits as a function of numerous variables for this internal assessment.

  • Experiment requirements – You will need to set up an environment in which you can measure the CO2 and ethylene levels of the fruit over a period of time.
  • Independent variables – Oxygen and temperature
  • Dependent variables – CO2 production, ethylene levels.

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5.Cleaning products and their effects on seed development

Next, you could measure the effect that household cleaning products have on seed germination. This internal assessment will be useful for your IB class, as you can investigate whether household cleaning products positively or negatively affect germination.

  • Experiment requirements – You need to create environments where you can expose plant seeds to plant seeds to different household cleaning solutions and record the results.
  • Independent variables – The different household cleaning products.
  • Dependent Variables – Germination rate of the seeds

6. Auxin hormone and light colour efficacy

The hormone auxin plays a key role in directing plant growth. However, this internal evaluation finds out whether the type of light increases or decreases its efficacy.

  • Set-up requirements – Place a seed in the dark environment with a single light source and observe how the change in light colour influences the success of phototropism.
  • Independent variables – The colour of the light
  • Dependent variables – The degree of plant growth towards the light source.

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7.The effects of the environment on milk spoilage

As we all know, milk spoils. This is due to the reproduction and development of lactobacilli. This is another exciting internal Biology assessment, as you can test the rate of spoilage depending on a lot of environmental conditions.

  • Experiment requirements – For this experiment, you need to compare the spoilage of milk and measure how quickly it spoils under different climates. For example, you can change the temperature, sunlight or even the type of milk.
  • Independent variables – Type of milk (skimmed or whole), variation in sunlight, temperature, etc.
  • Dependent variables – The rate at which the milk spoils quickly or slowly due to the above variables.

8.Reaction time with age

Another internal assessment you can make for Biology is reaction time with age. It is obvious that many people assume that reaction time decreases dramatically with age, so why not check if this is true? The only real downside to doing this as an internal assessment is that it can be quite difficult to find enough willing applicants.

  • Experiment Requirements – The best way to measure your reaction time is to take a ruler. In this case, you will need to drop a ruler from a given height and see if they can catch it.
  • Independent Variables – Age, take into account their eyesight, hearing and mobility.
  • Dependent variables – the time it takes to catch the ruler after dropping it.

What makes a good internal assessment in biology?

After reading the above, I hope you now have a general idea of the Biology Internal Assessment you are going to take to complete your IB class. However, choosing one at random may not be the best option, and you should consider the following to ensure that you have a ‘good’ internal assessment.

The best types of Internal Assessments in biology are those in which you are generally interested in research. Including this, you must show that you have done in-depth research and that you now fully understand the project.

To get an excellent internal assessment in biology, it doesn’t necessarily have to be the most complex. But one thing your internal assessment does require is a clear research question, a coherent structure and an easy-to-follow personal commitment that quickly demonstrates the student’s knowledge of the topic.

Hopefully, having read the above, it has fired your imagination, and you can now finalise your Biology Internal Assessment. Now what are you waiting for – get experimenting!