Microbiology Biology 41

Stavneysp97 Name

Lab Quiz 4

25 points total.

Match the description on the left with the appropriate answer in the list on the right. For answers with multiple letters, like "abd", fill in the answer rectangle for ALL of the letters ("a" AND "b" AND "d").

1. The breakdown of red blood cells a. nutrient agar

performed by pathogenic Streptococcib. mannitol salt agar

c. Sabouraud agar

2. Bacteria that are oxidase negative, gramd. blood agar

negative rods, facultatitvely anaerobic, and e. bacitracin

mesophilicab. alpha ( )hemolysis

ac. beta ()hemolysis

3. The specific species used to make bread risead. gamma ()hemolysis

ae. oxidase

4. An organism resistant to high osmoticbc. catalase

pressure (salt) and low pH, produces coagulasebd. coagulase

be. trehalose

5. A coenocytic mold that produces asexualcd. indole

sporangiosporesce. enterics

de. Rhizopus stolonifer

6. An organism that causes pharyngitisabc. Streptococcus pyogenes

(infection of the throat)abd. Streptococcus pneumoniae

abe. Rhodoturula rubra

7. A growth medium that is BOTH selective acd. Candida albicans

and differentialace. Aspergillus

ade. Penicillium

8. A yeast that causes vaginitisbcd. Staphylococcus aureus

bce. Saccharomyces cerevesiae

9. An important substance involved in

differentiating between Streptococcus

pyogenes and Streptococcus pneumoniae

10. An important substance involved in

differentiating between streptococci and

staphylococci.

11. A growth medium that contains catalase

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12. When using the Enterotube, what do you do next immediately after breaking off the wire rod at the dented mark?

a. Screw the end caps back on loosely

b. Inoculate each chamber using the wire rod

c. Punch out the 8 small air holes with the short wire piece

d. Dispose of the wire end piece in the autoclave waste

e. Use a loop to burn a hole over the MRVP and Indole chambers

13. Using the key below, determine the name of the organism which has the following characteristics:

•coccus shaped

•colony color is yellow-red

•coagulase is not produced

•mannitol is not fermented

•glucose is not fermented

•cells are arranged in groups of four

•catalase is produced

•not hemolytic

•trehalose is fermented

  • gram positive

a. Micrococcus luteus

b. Staphylococcus saprophyticus

c. Staphylococcus arlettae

d. Staphylococcus aureus

e. Planococcus

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TRUE/FALSE Answer “a” if true, and “b” if false.

14. The balloon placed over the end of the U-shaped glucose-yeast tubes was supposed to show the production of any oxygen gas by microbes in the tube.

15. A yeast is a filamentous, unicellular organism with septate hyphae.

16. The pH of the skin is around 7.

17. Streptococcus bacteria do not produce catalase.

18. The gram stain is a useful test in separating the different kinds of bacteria that live on the skin.

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19. Which of the pictures above shows what Candida albicans might be expected to look like under the microscope? (Answer A-E)

20. Which of the pictures above shows what a specific mold species might look like which grows on fruit, has white hyphae, produces green spores, and produces the first antibiotic discovered by humans? (Answer A-E)

21. Which bacterial substance is probably produced to help the organism “hide” from the human immune system?

a. coagulase

b. hemolysin

c. catalase

d. sebum

e. bile salts

22. Sebum is:

a. the substance produced by bacteria to hide from the immune system

b. the substance produced by bacteria to alter the pH of the skin

c. the substance added to respiratory tract bacteria to identify them

d. the substance produced by oil glands in human skin

e. the clear liquid remaining behind after red blood cells are lysed

23. One can safely conclude that a colony growing on a mannitol salt agar plate with a yellow halo around it is :

a. soluble in bile salts and resistant to optochin

b. not soluble in bile salts and resistant to bacitracin

c. tolerant of high salt and low pH

d. able to ferment mannitol and live in high salt

e. hemolytic to some degree, and bile salt tolerant

24. Alpha hemolysis on a blood agar plate can be described as:

a. no clearing or change in the blood agar medium

b. a bluish-white halo around a colony

c. a yellow halo around a colony

d. a green, cloudy zone around a colony

e. a clear zone around a colony

25. What does Sabouraud agar contain that makes it suitable for culturing fungi?

a. high salt

b. low pH

c. optochin

d. sebum

e. phenol red

Microbiology Bio 41 Quiz 4 pg 1