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

B. all of these are correct

C. it increases contrast to allow for better visualization

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. staphylococci

B. streptobacilli

C. streptococci

D. tetracocci

Question #3

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

A. Use bacteria from an isolated colony

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

C. Two of these are correct

D. Use bacteria from different colonies

Question #4

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

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

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

C. All of these are appropriate

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 macroscopic population of identical cells growing on agar

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

Question #6

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

A. TRUE

B. FALSE

Question #7

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

A. Two of these are correct

B. Cellular arrangement

C. Cell morphology

D. Concentration of ribosomes