Microbiology Lab Exam 2025 Questions & Answers with 100% Correct Answers | Verified

Considering the cultures used to inoculate each medium in this exercise, how many different microbial types should you expect to see in/on each medium? (1.4) - You should only have 1 if using good sterile technique. A successful aseptic transfer will have only micrococcus lutes growth- this would be a pure culture You were asked to describe differences in appearance of growth in each culture, if present. In which medium was this the most difficult to determine? What made it difficult? (1.4) - More difficult to see in broth because you can only see if growth occurred on the top or bottom etc. Better in slant because you can observe different growth patterns. Which medium was most difficult for you to transfer from? Which medium was most difficult for you to inoculate? Why? (1.4) - Most people don't like working with slants (solid) If you got growth on sterile NA and NB slant rubes, why? (1.4) - Possible contamination include not heating the loop to orange-hot, not holding the open tubes on an angle, and/or placing the cap on the table surface during the process. Did you notice a difference in density (turbidity) of growth in NB tubes inoculated from NB and NA slants? Possible reasons?( 1.4) - Generally, more cells are transferred from growth on a solid medium than from a broth culture. Therefore, broth cultures made from growth on a solid medium will show greater turbidity than those inoculated from a broth culture. Did you notice a difference in density of growth on NA slants inoculated from NA slants and NB? (1.4) - Generally there will be denser growth on the slant inoculated from the NA slant, because more cells are transferred from solid medium than broth. Pure culture (1.4) - When a culture ( a medium that contains living microbes) contains a single species. Broths (1.4) - A medium used to grow microbes when fresh cultures or large numbers of cells are required. Used for ID.