22 Biology IA Topic Ideas

Written By IB++ Tutor Zohaib N.

Internal Assessment

Are you looking for some IB Biology Internal Assessment (IA) ideas?

The internal assessment requirements are the same for biology, chemistry and physics. The internal assessment, worth 20% of the final assessment, consists of one scientific investigation. The individual investigation should cover a topic that is commensurate with the level of the course of study. Student work is internally assessed by the teacher and externally moderated by the IB. The performance in internal assessment at both SL and HL is marked against common assessment criteria, with a total mark out of 24.

The task will have the same assessment criteria for SL and HL. The five assessment criteria are personal engagement, exploration, analysis, evaluation and communication.

Internal assessment criteria the new assessment model uses five criteria to assess the final report of the individual investigation with the following raw marks and weightings assigned:

  • Personal engagement 2 (8%)
  • Exploration 6 (25%)
  • Analysis 6 (25%)
  • Evaluation 6 (25%)
  • Communication 4 (17%)
  • Total 24 (100%)


Here is a list of top 22 Biology Internal Assessment (IA) ideas:

  1. How do the factors temperature and light intensity that affect photosynthesis balance out each other when it comes to the time taken for photosynthesis to occur?
  2. How does increasing the concentration of Oxytetracycline in mg/L affect root elongation in cm of Citrus limon?
  3. How does cumin and turmeric powder, in comparison to indigestion tablets, affect the rate of neutralization of hydrochloric acid, measured by the difference of change of pH levels in 5 minutes?
  4. How does different concentrations of Gibberellic acid affect the germination of a dolly Parton rose?
  5. To what extent does the mass of sodium nitrate powder have an effect on the quality of beef as a preservative
  6. How does different sodium chloride concentrations affect seed germination in the bougainvillea plant?
  7. How does different conditioners affect the strength of hair?
  8. How does extract of the seeds and the leaves of the moringa plant (herbal medicine) show antifungal activity against the Malassezia yeast (Pittosporum) fungi that causes dandruff?
  9. How does the concentration of zinc chloride affect the growth of plaque?
  10. How effective are synthetic antibacterial products compared to natural antibacterial products against the growth of Cut bacterium acnes?
  11. What brand of laundry detergent is the most effective in the digestion and removal of lipid stains?
  12. How does the pH level of watering solution affect the growth and development of chickpea (Cicer arietinum) and mung bean (Vigna radiata) over a time period of 5 days indicated by the length of the stem measured?
  13. How would changing (storage) temperatures affect the rate of change of pH of different types of milk due to spoilage?
  14. How does the acidity of different beverages affect the deterioration of tooth enamel? (Use egg as imitation of tooth)
  15. How does a sudden and intensive workout affect the heart rate, and to what extent does warm up have an impact on the maximum heart rate?
  16. How do different concentrations of lactases affect the breakdown of disaccharides like lactose in milk effectively?
  17. How does the composition of soil affect the growth of runner Plants from the original plant?
  18. How does stomatal density change according light exposure of red and blue light?
  19. How does the percentage of salinity in water affect the rate of growth of radishes in mass?
  20. How do natural antiseptics (ginger and turmeric) compare with commercial antiseptics in the inhibition of growth of e. coli bacteria?
  21. What effect does temperature have on the ripening process of a fruit?”
  22. Investigate the influence of Ph levels in the soil on the development of the Lepidium avitum 2) How does the concentration of potassium chloride affect the growth of Lepidium savitum.


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