MICROBIOLOGY LAB EXAM 1 QUESTIONS AND CORRECT ANSWERS 2025/2026

MICROBIOLOGY LAB EXAM 1 QUESTIONS AND CORRECT ANSWERS 2025/2026 Total magnification is - Answer -Objective lens × 10 Why is old immersion used with the 100x objective? - Answer -Causes less light refraction therefore focusing more light into the lens What is the function of the Iris diaphragm? - Answer -Opens and closes the cover over the light What is the advantage of the parfocal lenses? - Answer -When magnification changes the object stays in focus What can influence the resolution of a bright field microscope? - Answer -Wavelength of light and numerical aperture What is the significance of Agar as an ingredient in culture media? - Answer -It causes liquid culture media to become solid What are the signs of growth in a liquid medium? - Answer -Pellicle on surface, sediment on bottom, and uniform cloudiness Why do we disinfect the bench top before and after our laboratory period? - Answer -To ensure that no organisms are left over and could contaminate somethingWhat is a binomial name? - Answer -A way to name something by using two names Why are culture tubes held somewhat horizontally when transferring cells rather than vertical? - Answer