Question 1

Which gene on the pGLO plasmid is responsible for making bacteria resistant to ampicillin?

Accepted Answer

bla

Question 2

What is the function of the araC gene in the pGLO plasmid?

Accepted Answer

It encodes a transcription factor that regulates GFP expression in the presence of arabinose.

Question 3

Why do only a small percentage of bacteria survive on LB/amp plates after transformation with pGLO?

Accepted Answer

Only bacteria that have taken up the pGLO plasmid express beta-lactamase and survive.

Question 4

What is the role of arabinose in the pGLO transformation experiment?

Accepted Answer

It binds to araC, allowing transcription of the GFP gene.

Question 5

If you plate transformed bacteria (+pGLO) on LB/amp/ara plates, what phenotype do you expect to observe under UV light?

Accepted Answer

Growth with green fluorescence.

Question 6

Which of the following best describes the process of 'heat shock' in bacterial transformation?

Accepted Answer

It temporarily makes bacterial membranes permeable to DNA.

Question 7

What would you expect to see on a plate containing LB only, inoculated with (-)pGLO bacteria?

Accepted Answer

Growth, no fluorescence.

Question 8

Why is the beta-lactamase gene described as being 'constitutively expressed'?

Accepted Answer

It is always expressed, regardless of environmental conditions.

Question 9

A student forgets to add arabinose to the LB/amp plate when plating +pGLO bacteria. What is the expected result under UV light?

Accepted Answer

Colonies will grow but will not fluoresce.

Question 10

Which of the following best explains why the pGLO plasmid contains an origin of replication (ori)?

Accepted Answer

To allow the plasmid to replicate independently of the bacterial chromosome.

Question 11

If you observe white colonies on an LB/amp/ara plate inoculated with +pGLO bacteria, what is the most likely explanation?

Accepted Answer

The arabinose was not present or the GFP gene was not expressed.

Question 12

Which of the following scenarios would result in no bacterial growth?

Accepted Answer

(-)pGLO bacteria plated on LB/amp.

Question 13

What is the primary purpose of using ampicillin in the bacterial transformation experiment?

Accepted Answer

To select for bacteria that have taken up the pGLO plasmid.

Question 14

A researcher wants to confirm that the GFP gene is only expressed in the presence of arabinose. Which plates should they compare?

Accepted Answer

LB/amp (+pGLO) and LB/amp/ara (+pGLO)

Question 15

Which of the following best describes the relationship between the presence of arabinose and GFP expression in pGLO-transformed bacteria?

Accepted Answer

GFP is expressed only when arabinose is present.

Question 16

If a mutation in the araC gene prevents it from binding arabinose, what would be the expected result on an LB/amp/ara plate with +pGLO bacteria?

Accepted Answer

Colonies would grow but not fluoresce.

Question 17

Which step in the transformation protocol is most critical for allowing the plasmid DNA to enter the bacterial cells?

Accepted Answer

Heat shock at 42°C

Question 18

A student accidentally adds pGLO plasmid to both the (+)pGLO and (-)pGLO tubes. What is the most likely result on the LB/amp plate inoculated with the (-)pGLO tube?

Accepted Answer

Growth, possibly with fluorescence if arabinose is present.

Question 19

Which of the following equations best represents the selection process for transformed bacteria in this experiment?

Accepted Answer

$$	ext{Transformed Bacteria} + 	ext{Ampicillin} ightarrow 	ext{Growth}$$

Bacterial Transformation and the pGLO Plasmid: Principles and Laboratory Protocol

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