Biotechniques Fall 2023 _Bacterial culture revision_22

A ________Blank is a mound of cells on a solid medium that represents the progeny from one original bacterial cell.

• Culture

• Quadrant

• Streak

• Colony

The colony results from a single cell or a cluster of cells multiplying into a visible mass.

• True

• False

An indirect method of estimating bacterial numbers is based on the turbidity of the sample. A ________Blank can be used to determine the turbidity by measuring absorbance.

• Balance

• Spectrophotometer

• Dilution sample

• Colony counter

To prevent the introduction of unwanted organisms into an environment or culture, ________Blank technique is used.

• Aseptic

• Serial dilution

• Sterile

• Ultraviolet

Which of the arrows is pointing to an isolated colony?

• Arrow A

• Arrow B

• Arrow C

Plate ________Blank shows a correctly performed streak plate.

• A

• B

• C

What parts of the transformation procedure are done to increase the competence of the bacterial cells?

• Treatment with calcium

• Using a microcentrifuge

• Adding LB to the tube

• Brief heat shock

Match the following

• bla

• Regulatory protein that affects the transcription of the gene for green fluorescent protein

• araC

• Gene that encodes green fluorescent protein

• GFP

• Encodes resistance to ampicillin

• ori

• DNA polymerase begins replicating the plasmid at this site

What is the role of arabinose in the transformation procedure?

• It is an inducing substrate that allows the transcription of the gene of interest.

• It is a required nutrient for any bacteria to grow.

• It is a repressing substrate that turns off the transcription of pGLO.

• It selects for nontransformed cells whereas ampicillin selects for transformed bacteria.