Question: When streaking a plate for isolation of colonies (“streak plate technique”), you should increase the loop between each section streaked.

Answer Choices:
True
False

Answer: True

 

Question: The microscope lens that focuses light from its source is the:

Answer Choices:
Condenser
Ocular
Objective

Answer: Condenser

 

Question: What is the dilution factor, if you conducted a serial dilution of 0.1 mL of stock culture added to 9.9 mL PSB?
10^-3

Answer Choices:
10^-2
10^-1
10^-4

Answer: 10^-2

 

Question: Bobtail squid:
Acquire new symbionts every day

Answer Choices:
Expel 5% of their symbionts every morning at dawn
Expel 95% of their symbionts every day at dawn
Don’t have symbionts

Answer: Expel 95% of their symbionts every day at dawn

 

Question: Microscope lenses can routinely be cleaned with paper towels.

Answer Choices:
True
False

Answer: False

 

Question: You have a 35X objective lens in place, and the numerical aperture of the objective lens is 0.75. The numerical aperture of the condenser lens is 1.25. What is the total magnification if the ocular lens is 10X, with the eyepieces spaced 3 cm apart?

Answer: 350X

 

Question: Which of the following organisms has a chained cellular arrangement?

Answer Choices:
Bacillus subtilis
Streptococcus pyogenes
Escherichia coli
Staphylococcus aureus

Answer: Streptococcus pyogenes

 

Question: A broth has 2.20 x 10^8 CFU/mL. Approximately how many CFUs would you expect to count if you plated 0.5 mL? Please provide WHOLE number, NO EXPONENTS.

Answer Choices:
220 CFU
22 CFU
2 CFU
110 CFU

Answer: 110000000

 

Question: Entamoeba coli causes the disease amoebic dysentery.

Answer Choices:
True
False

Answer: False

 

Question: You want to determine the cell density of a liquid bacterial culture so you perform a serial dilution. You inoculate three TSA plates with 100 µl aliquots from three consecutive dilution tubes. After incubation, you count the colonies counts on each plate and obtain the results listed below. Which plate should be chosen to calculate the original cell density (OCD).

Answer Choices:
Plate A: TNTC
Plate B: 342 CFU
Plate C: 43 CFU

Answer: Plate C

 

Question: Which of the following is an example of an electron carrier:
ATP

Answer Choices:
NADH+
Pyruvate
G-3-P

Answer: NADH+

 

Question: The disinfectant used to wipe down the laboratory bench every class period is effective at sterilizing the bench.

Answer Choices:
True
False

Answer: False