) If you counted 500 CFU’s in the petri dish for number 6 and 5000 CFU’s in petri dish for number 7, what would be the most justifiable explanation for this? 19) If the original sample’s concentration was 12 bacterial cells, what do you expect the count to be?

If 1.0 mL of a 1:1000 dilution produces 200 colonies on a culture plate, how many bacteria were present per mL in the original (undiluted) sample? 200,000 20,000 2,000 200

You have several different media onto which you inoculated eight strains of yeast (A-H). The media include a rich medium, an unsupplemented minimal medium, and minimal media each supplemented with one vitamin. Of the yeast strains, one is a prototroph and seven are auxotrophs for a vitamin. After overnight incubation, the following results were observed (tan patches represent growth): D plate 1 (A) B DE F GH plate 5 plate 4 plate 6 Which plate contains an unsupplemented minimal medium? [Select] Which plate contains a rich medium? [Select] plate 2 Which strain is a prototroph? [Select] Strain E is an auxotroph for niacin. Which plate reveals this specific auxotrophy? [ Select] plate 3 plate 7 One strain is an auxotroph for both choline and pantothenic acid. Which one is this most likely to be? [Select]

You are added 60mL of soil slurry to 540mL of sterile water. You can transferred 1000uL of that dilution to 9 mL of water. You then prepared a 10-7 dilution from that tube. You finally transfer 1 uL of that to a TSA plate. After 48 hours, you counted 32 colonies on quarter of the plate. (A) How many cells/mL were present in the original soil sample? (B) How many colonies would be present on the plate if you would have plated 1mL of the last sample? (C) How many milliliters would you need to prepare a 10-4 from 100uL of sample?