Exam 3: Tools of the Laboratory: Methods of Studying Microorganisms

You are doing research on a bacterial species, trying to determine the shape, distribution, and arrangement of a number of filamentous structures that protrude from the cell surface.Which type of microscopy would best enable you to do this?

The correct microbiological term for the tiny sample of specimen that is put into a nutrient medium in order to produce a culture is the _____.

Which method often results in colonies developing down throughout the agar and some colonies on the surface?

At the end of the Gram stain, gram-positive bacteria will be seen as purple cells.

Scanning tunneling and atomic force microscopes are used to image the detailed structure of biological molecules.

A student was given a stained smear to observe.Upon observation, the student noted rod-shaped bacteria that were clear and unstained against a darker background.What sort of stain was performed on this slide?

A microbiologist decides to use a nutrient medium that contains thioglycolic acid.What type of microbe is she attempting to culture?

Newly inoculated cultures must be _____ at a specific temperature and time to encourage growth.

A microbiologist inoculates Staphylococcus aureus into a culture medium.Following incubation, both Staphylococcus aureus and Staphylococcus epidermidis are determined to be growing in this culture.What is the most likely explanation?

Which of the following places the steps for microbial culture and identification in the correct order?

Syphilis is diagnosed either with microscopy or serology because the causative agent (Treponema pallidum) does not grow on any microbiological media.Which term best describes this aspect of the T.pallidum?

Which of the following will result when 1% to 5% agar is added to nutrient broth, boiled and cooled?

All of the following are diameters of cells that would be resolved in a microscope with a limit of resolution of 0.2 µm except

A microbiologist must culture a patient's feces for intestinal pathogens.Which of the following would likely be present in selective media for analyzing this fecal specimen?

A nutrient medium that has all of its chemical components identified and their precise concentrations known and reproducible would be termed

Fixed smears of specimens are required in order to perform the Gram stain and endospore stain on the specimens.

Sally had a throat sample taken at a satellite lab within her health care provider's office.What kind of media would be best suited for maintaining the quality of this specimen prior to its arrival in the clinical laboratory?

The wavelength of light used plus the numerical aperture governs

A contaminated food sample contains several different species of bacteria.A food microbiologist is interested in studying just one of these species.Describe the sequence of procedures that the microbiologist must perform in order to obtain a pure culture of the bacterial species of interest from this food sample.Detail all the necessary media and equipment.

Which of the following reagents reacts with crystal violet as the mordant?