Los Angeles City College » Microbiology » Microbiology 020 - General Microbiology » Fall 2020

Question #1

Staining bacteria before observing them under the microscope is helpful because…

A. all of these are correct

B. it increases contrast to allow for better visualization

C. it allows you to observe shape and arrangement of the organism

D. it enables detection of microbes indicating the patient has an infection

Question #2

Bacteria that are spherical and connected end-to-end (in a chain) are known as…

A. streptococci

B. staphylococci

C. streptobacilli

D. tetracocci

Question #3

Which of the following would be appropriate for choosing a sample to perform a smear preparation?

A. Use bacteria from different colonies

B. Use only a small amount of bacteria on the loop

C. Use bacteria from an isolated colony

D. Two of these are correct

Question #4

Which of the following best describes the correct method for heat fixation?

A. All of these are appropriate

B. You should hold the slide in the blue part of the flame for 5 seconds

C. The heating of the slide should be extensive. The color of bacteria on the slide should become brownish.

D. The heating should be very brief. Passing the slide through the blue part of the flame for 3-5 seconds is enough

Question #5

What is a bacterial smear?

A. All of these are correct

B. A sample of bacteria that has been streaked across the surface of agar

C. A thin film or layer of bacteria or other specimen that has been spread across the surface of a glass slide

D. A macroscopic population of identical cells growing on agar

Question #6

The simple stain provides enough information about a microbe to clearly identify its species.

A. FALSE

B. TRUE

Question #7

Which of the following could be determined through simple staining of a microbial smear?

A. Cell morphology

B. Cellular arrangement

C. Concentration of ribosomes

D. Two of these are correct