Lab Quiz 5

Question 1

“You grow bacteria in phenol red broth, and after a few days you observe that the broth has turned a yellow colour. What does this indicate about the species?”

a) It does not ferment anything in the medium
b) It ferments both proteins/peptides and carbohydrates in the medium
c) It ferments proteins or peptides in the medium
d) It ferments carbohydrates in the medium

Answer 1

d) It ferments carbohydrates in the medium

Question 2

The gas bubble that is observable in a Durham tube in the phenol rest test is made up of oxygen gas

a) True
b) False

Answer 2

b) False

Question 3

Biles salts and crystal violet inhibit the growth of Gram positive bacteria in:

a) Eosin methylene blue (EMB) agar
b) Phenol red broth
c) MacConkey agar
d) Starch hydrolysis

Answer 3

c) MacConkey agar

Question 4

Eosin methylene blue (EMB) agar inhibits the growth of all Gram positive bacterial species.

a) True
b) False

Answer 4

b) False

Question 5

Which of the following tests is used to determine whether bacteria are part of the enteric group?

a) Catalase test
b) MacConkey agar
c) Gelatin hydrolysis
d) Phenol red broth

Answer 5

b) MacConkey agar