Whats the indep, dependant, and control variables?

In 1928 Sir alexander fleming was studying staphylococcus bacteria in grown culture dishes. he notices a mysterious mold also growing in some of the dishes. a clear zone existed around the unknown mold





all of the bacteria that had grown in this clear zone had died. in the culture dishes without the mold no clear areas were present





Fleming reasoned that the mysterious mold must be producing a chemical that killed the bacteria. he decided to isolate this substance and then test it to see if it would kill bacteria.














Fleming transferred the mold to a nutrient broth solution. (this solution contained the materials the mold needed to grow and reproduce)





he allowed the mold to grow, then he removed the mold form the broth. Fleming added the nutrient broth in wihch the mold had grown to teh bacteria.





He observed that the bacteria were killed. Fleming added nutrient broth that did not have the mysterious mold growing in it to another dish of bacteria. the bacteria in this dish were not killed.Whats the indep, dependant, and control variables?
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