Explain the results in the sterilized and not-sterilized broth?

So that the culture doesn't become contaminated, which can lead to loss of batch.

Removal of all bacteria and viruses.

uncontaminated, axenic

Sterilized means that all the bacteria and viruses have been removed or killed, such as by UV irradiation or boiling. Sterilized water is not necessarily pure and could still be toxic, as it could...

Aural thermometers have nowadays eliminated this need. But dipping a clinical (mercury) thermometer in an alcohol solution will adequately sterilize it.