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1. The image here shows four different genera of bacteria growing in nitrate broths (tube 1 is a pure culture of one genus, tube 2 a pure culture of another genus etc.). After incubation alpha-napthylamine and sulfanilic acid were added to all four tubes. When no color change occurred in tubes 3 and 4, zinc dust was added to those tubes only. Based on these results (see image), which tubes would be recorded as a positive nitrate reduction test?
2. Observe the results in the image shown for question 1. What is the correct conclusion?
3. The image here presents the results of the urease test for two different bacteria. The organism that produced the result at the arrow is lactose negative and produces hydrogen sulfide on KIA media. This organism probably
4. This image shows two different organisms growing on blood agar. If the two disks with "O" on them contain optochin, what conclusion can be drawn about the organism at the arrow?
5. A pure culture of bacteria was inoculated into the broth culture in tube 1. A pure culture of another genus of bacteria was inoculated into tube 2. After incubation, both genera of bacteria produced equally turbid (cloudy) cultures. Desoxycholate (bile) was added to both tubes and the results are shown in the image. Which conclusion is correct?
6. Test results for four different genera of bacteria on KIA media are shown here. The bacteria that produced the result in Tube 3
7. This image shows the test results for two different bacteria. The organism in box 2 is
8. This image shows the results of four different genera of bacteria inoculated into thioglycollate media and incubated for 24 hours. Growth occurred for each tube between the blue arrows. Which of the following is the correct conclusion?
9. The primary function of the equipment shown in this image is to _____ for the cultures inside the jar.
10. The primary function of the equipment shown in this image is to _____ for the cultures inside the jar.