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 increases contrast to allow for better visualization

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

C. all of these are correct

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

Question #2

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

A. streptococci

B. tetracocci

C. streptobacilli

D. staphylococci

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 bacteria from different colonies

C. Two of these are correct

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

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

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

Question #5

What is a bacterial smear?

A. A macroscopic population of identical cells growing on agar

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

C. All of these are correct

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

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. Cellular arrangement

B. Cell morphology

C. Concentration of ribosomes

D. Two of these are correct