In 1928, sir alexander fleming was studying staphylococcus bacteria growing in culture dishes. he noticed that a mold called penicillium was also growing in some of the dishes. a clear area existed around the mold because all the bacteria that had grown in this area had died. in the culture dishes without the mold, no clear areas were present. write an "if/then" hypothesis for this observation.

The correct answer is - if mold present then it produces some chemical that kills the bacteria.

Explanation:

A hypothesis is an assumption or a guess based evidence already existed for explanation or arguing so that it can be tested.

Sir Alexander Fleming found that the bacteria around penicillium mold are dead whereas the culture dishes with no mold have no clear area of dead bacteria.

On the basis of the following evidence, one can hypothesize that If penicillium mold produce then it produces some chemical that kills the bacteria.

Thus, the correct answer is - if mold present then it produces some chemical that kills the bacteria.

A mold was developing in some of the culture dishes used by Sir Alexander Fleming and was eliminating some of the bacterial population. The hypothesis is that the mold was generating a chemical, which was toxic to the bacteria in the dishes and killed them.

The hypothesis was examined by separating the Penicillium and administering it into the solution of nutrient broth. After the growth of Penicillium it was withdrawn from the broth. The broth was then eventually supplemented to the bacteria and the bacteria died. Thus, it can be concluded that the hypothesis is supported.