Plasmid and cDNA Library Quiz

What is the role of the origin of replication (ori) in a plasmid?

• To confer antibiotic resistance

• To initiate DNA replication

• To cut DNA at specific sequences

• To bind regulatory proteins

Which enzyme is responsible for joining sticky ends of DNA fragments in recombinant plasmid formation?

• DNA polymerase

• RNA polymerase

• DNA ligase

• Restriction enzyme

How can researchers confirm that bacteria have taken up a recombinant plasmid?

• By observing bacterial growth in the absence of antibiotics

• By testing for fluorescence in the presence of arabinose

• By checking for the presence of viral particles

• By measuring bacterial size

What characteristic of restriction enzymes allows them to cut DNA at specific sites?

• They recognize specific protein sequences.

• They bind to the plasmid’s origin of replication.

• They recognize specific palindromic DNA sequences.

• They attach to antibiotic resistance genes.

In the pGLO plasmid, what happens when arabinose is present?

• The plasmid is destroyed.

• Antibiotic resistance is lost.

• The GFP gene is expressed.

• DNA replication is halted.

What is the first step in creating a cDNA library for cloning a gene?

• Amplify cDNA by PCR

• Obtain DNA source

• Isolate a specific cDNA by electrophoresis

• Carry out subcellular fractionation

Why can't bacteria process eukaryotic genomic DNA directly?

• It is too large

• It contains introns

• It has a different sugar backbone

• It is chemically unstable

What is the role of reverse transcriptase in creating a cDNA library?

• It removes introns from mRNA

• It synthesizes mRNA from DNA

• It generates DNA from an mRNA template

• It sequences the DNA

Which of the following is used to amplify DNA sequences?

• Southern Blotting

• Reverse transcriptase

• Affinity chromatography

• Polymerase Chain Reaction (PCR)

How are specific cDNA sequences identified in a cDNA library?

• By sequencing the entire library

• Using a labeled probe in Southern Blotting

• By visual inspection of the gel

• By using a mass spectrometer