Unit 2--Lab Quizzes (4-6)

Question 1

Which of the following microbes causes malaria?

Plasmodium falciparum

Giardia lamblia

Balantidium coli

Trichomonas vaginalis

Answer 1

Plasmodium falciparum

Question 2

Trichomonas vaginalis differs from many other protozoa because it does not form what structure?

Cell wall

Nucleus

Endospore

Cyst

Answer 2

Cyst

Question 3

Which mold had asexual spores that appeared like little footballs?

Fusarium racemosum

Penicillium chrysogenum

Rhizopus stolonifer

Syncephalastrum racemosum

Answer 3

Fusarium racemosum

Question 4

Which of these fungi is “black bread mold”?

Fusarium racemosum

Penicillium chrysogenum

Rhizopus stolonifer

Syncephalastrum racemosum

Answer 4

Rhizopus stolonifer

Question 5

What does CFU stand for?

Clifton Franklund unleashed

Colony forming units

Cryptic fungus units

Colony

Answer 5

Colony forming units

Question 6

What is the TDF for Tube A?

0.1 mL —> 9.9 mL (A)
1.0 mL —> 9.0 mL (B)
1.0 mL —> 9.0 mL (C)
1.0 mL —> 9.0 mL (D)
—> 0.1 mL plated
180 colonies

Answer 6

(0.1mL added + 9.9 mL) / 0.1 mL added

= 10 / 0.1

= 100

Question 7

What is the SDF for tube C?

0.1 mL —> 9.9 mL (A)
1.0 mL —> 9.0 mL (B)
1.0 mL —> 9.0 mL (C)
1.0 mL —> 9.0 mL (D)
—> 0.1 mL plated
180 colonies

Answer 7

Tube A TDF = 100

Tube B TDF =
(1.0 mL added + 9.0 mL) / 1.0 mL added
= 10 / 1.0 = 10

Tube C TDF =
(1.0 mL added + 9.0 mL) / 1.0 mL added
= 10 / 1.0 = 10

SDF = TDF A x TDF B x TDF C

=100 x 10 x 10

= 10,000 (10^4)

Question 8

How many CFU/mL were in the original flask?

0.1 mL —> 9.9 mL (A)
1.0 mL —> 9.0 mL (B)
1.0 mL —> 9.0 mL (C)
1.0 mL —> 9.0 mL (D)
—> 0.1 mL plated
180 colonies

Answer 8

SDF Tube D =
100 x 10 x 10 x 10

= 100,000 (10^5)

CFU/mL = (SDF x # of colonies) / mL plated

= (100,000 x 180) / 0.1 mL

= 1.8 x 10^8

Question 9

What is the first phase of bacterial growth?

Answer 9

Lag

Question 10

Using the points at 120 and 200 minutes, what is the slope (m) of the line?

Time: Absorbance:
120 0.059
200 0.501

Answer 10

m = ( log (Abs 2) - log (Abs 1) ) / (Time 2 - Time 1)

m = ( log (0.501) - log (0.059) ) / (200 - 120)

m = 0.0116

Question 11

Using the slope (m = 0.0116), what is the generation time (g) of the culture in minutes?

Answer 11

g = log (2) / m

g = log (2) / 0.0116

g = 26.0 min

Question 12

What is the second phase of bacterial growth?

Answer 12

Log (exponential)

Question 13

Using the g value (g = 26.0 min), what is the growth rate (k) of the culture in hours^-1?

Answer 13

k (min^-1) = 1 / g

k (hr^-1) = 60 / g

= 60 / 26.0

= 2.31 hr^-1

Question 14

What term refers to the holes seen in a bacterial culture?

Colonies

Plaques

Voids

Mycelia

Answer 14

Plaques

Question 15

What term refers to viruses of prokaryotic cells?

Yeast

Viroids

Phage

Prions

Answer 15

Phage

Question 16

What is the TDF for Tube A?

1.0 mL —> 9.0 mL (A)
1.0 mL —> 9.0 mL (B)
1.0 mL —> 9.0 mL (C)
1.0 mL —> 9.0 mL (D)
—> 10 uL (0.01 mL) plated
23 clear spots (plaques)

Answer 16

(1.0 mL added + 9.0 mL) / 1.0 mL added

= 10 / 1.0

= 10

Question 17

What is the SDF for Tube C?

Answer 17

Tube A TDF = 10

Tube B TDF =
(1.0 mL added + 9.0 mL) / 1.0 mL added
= 10 / 1.0 = 10

Tube C TDF =
(1.0 mL added + 9.0 mL) / 1.0 mL added
= 10 / 1.0 = 10

SDF = TDF A x TDF B x TDF C

=10 x 10 x 10

= 1,000 (10^3)

Question 18

What is the best estimate for the original viral titer?

1.0 mL —> 9.0 mL (A)
1.0 mL —> 9.0 mL (B)
1.0 mL —> 9.0 mL (C)
1.0 mL —> 9.0 mL (D)
—> 10 uL (0.01 mL) plated
23 clear spots (plaques)

Answer 18

SDF Tube D =
10 x 10 x 10 x 10

= 10,000 (10^4)

PFU/mL = (SDF x # of plaques) / mL plated

= (10,000 x 23) / 0.01 mL

= 2.3 x 10^7

Question 19

Which of the following microbes would grow best at pH 5?

Acidophile

Alkalinophile

Psychrophile

Aerobe

Answer 19

Acidophile

Question 20

Which is the following microbes would grow best at 5º C?

Neutrophile

Psychrophile

Anaerobe

Acidophile

Answer 20

Psychrophile

Question 21

Which if the following microbes would grow with no added salt and also 5% NaCl?

Acidophile

Psychrophile

Halotolerant

Halophile

Answer 21

Halotolerant

Question 22

Which of the following microbes would NOT grow with no added salt but would grow with 5% NaCl?

Acidophile

Psychrophile

Halotolerant

Halophile

Answer 22

Halophile

Question 23

What type of microbial growth is typified by Tube 5?

Tube 5: growth only at the bottom of the tube

Obligate aerobe

Obligate anaerobe

Facultative anaerobe

Aerotolerant

Answer 23

Obligate anaerobe

Question 24

What type of microbial growth is typified by Tube 6?

Tube 6: more growth at the top of the tube than the bottom

Obligate aerobe

Obligate anaerobe

Facultative anaerobe

Aerotolerant

Answer 24

Facultative anaerobe

Question 25

Where would an antiseptic most likely be used?

On your phone

Injected into your blood

In drinking water

On your arm

Answer 25

On your arm

Question 26

Where do we get most antibiotics from?

Archaea

Fungi

Algae

Protozoa

Answer 26

Fungi

Question 27

What term refers to the clear areas shown around disks on a bacterial culture?

Zones of inhibition

Plaques

Lytic zone

Attenuation

Answer 27

Zones of inhibition

Question 28

What size zone of inhibition shows that bacteria was susceptible to a drug?

Larger zones

Smaller zones

Answer 28

Larger zones