Microbiology Serial Dilution Quiz

What is the purpose of performing a serial dilution in microbiology?

• To increase the concentration of microorganisms

• To quantify the number of microorganisms in a sample

• To change the species of microorganisms

• To observe the color change in microorganisms

What does one colony on a dilution plate represent in a serial dilution process?

• 1 cell in the most dilute sample

• 1 cell in the original culture

• 10 cells in the original culture

• 100 cells in the original culture

What is the relationship between the density of the original culture and the dilution series in a serial dilution?

• The density of the original culture is directly proportional to the dilution series.

• The density of the original culture is inversely proportional to the dilution series.

• The density of the original culture is not related to the dilution series.

• The density of the original culture is the same as the dilution series.

What is the total volume of liquid in tube 2 after the transfer from tube 1?

• 10.0 mL

• 9.9 mL

• 10.1 mL

• 9.8 mL

What is the dilution factor between tube 1 and tube 2?

• 1:10

• 1:100

• 1:1000

• 1:10000

Which tube has the highest concentration of E. coli culture?

• Tube 1

• Tube 2

• Tube 3

• Tube 5

What is the dilution factor represented by the transfer from tube 3 to tube 4?

• 1:10

• 1:100

• 1:1000

• 1:10000

If 1 mL of liquid is transferred from tube 4 to tube 5, what is the new dilution factor in tube 5?

• 10^-6

• 10^-7

• 10^-8

• 10^-5

What is the first step in the dilution series depicted in the image?

• Transfer 1 mL of E. coli culture to the first test tube

• Perform a serial dilution starting with 0.1 mL of E. coli culture

• Add 9.9 mL of solvent to the E. coli culture

• Vortex the E. coli culture before any transfers

Which pipet should be used for a 0.1 mL transfer according to the image?

• Blue pipet with blue tips

• Yellow pipet with yellow tips

• No specific pipet is mentioned for a 0.1 mL transfer

• Any pipet as long as it measures 0.1 mL