Calculating Zones of Inhibition
To compare antibiotics, we measure the area of the "clear zone" around an antibiotic disc on an agar plate.
Which mathematical formula do we use to find the area of the zone?
What is Calculating Zones of Inhibition?
"The zone of inhibition is a circular area around an antibiotic disc where bacterial growth is suppressed."
Which statement accurately describes calculating zones of inhibition at a GCSE level?
In a zones of inhibition investigation, what does a larger clear zone around a disc usually show?
To calculate the area of a circular zone of inhibition, which measurement is needed first?
If a zone of inhibition has a diameter of 10 mm, what is its radius?
Measuring Effectiveness
The clear zone where bacteria haven't grown is called the zone of inhibition.
Measure the diameter of the zone with a ruler.
Calculate area using Area = πr².
A larger zone of inhibition means the antibiotic is more effective at killing that specific bacteria.
Want to improve faster?
The fastest way to improve your grade is to practise exam-style questions, identify your gaps, and focus only on what you don't know.
Related GCSE Biology Questions
Verified for 2024/25 Exams
Aligned to current UK Science Specifications
Little & Often Content Team
Science Education Specialists