Chapter 3
Supplemental Quiz

1. The labels have been accidentally removed from four (4) transmission electron micrographs of single cells. You know that one micrograph is of the Gram-negative bacterium E. coli, another is the Gram-positive Staphylococcus aureus, the third is the Gram-positive bacterium Bacillus cereus and the last is the bacterium Mycoplasm pneumoniae. Describe the mechanism to correctly re-label the micrographs.

2. Describe the use of a culture medium that (a) contains an agent that inhibits the growth of Gram-negative bacteria and (b) glows lime green in the presence of amino acids. What type of bacteria would be cultivated on this media? Defend your answer in 2-3 sentences.

3. Propose one mechanical and one culturing technique that would separate three bacteria mixed together in a soil sample. What conditions are required for successful isolations of pure cultures?

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