Date Posted: 09/03/2026Current News
Category / School News Posted on: 03/03/2026
GCSE Biology Practical Investigation
Our GCSE Biology pupils have been working on a practical investigation exploring how different substances can slow or stop the growth of E. coli.
This experiment helps them understand how scientists test antibiotics and disinfectants while developing careful lab and data-handling skills.
In this practical, pupils prepare agar plates containing E. coli and place small discs soaked in different substances onto the surface.
As the bacteria grow, clear circles called zones of inhibition form around discs that have been effective. The bigger the clear area, the stronger the antimicrobial effect. Pupils take measurements after 24, 48 and 72 hours to track how each substance works over time.
Comparing the sizes of the inhibition zones helps them see which treatments act quickly, which continue to expand, and which show little impact.
This activity also teaches the importance of a controlled experiment. Pupils keep key factors the same such as temperature, disc size and agar conditions so their results are valid and reliable.
They then record their measurements, compare findings and reflect on how the method could be improved, and we look forward to the thoughtful conclusions they will draw from their results.
