Why is the clear area surrounding an antibiotic disk called the zone of inhibition?

No bacteria grows in surrounding area of antibiotic disk, thus it is known as zone of inhibition

Explanation:

The area surrounding an antibiotic disk is called the zone of inhibition because in this region bacteria & its colonies are unable to grow. Due to the anti microbial effect produced by bacteria, there is no visible sign of presence of bacteria in the inhibition region.

Also,  the zone of inhibition also depicts susceptibility of bacteria towards the effect of antibiotics.

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