lab7

What is the primary function of restriction enzymes in molecular cloning?

• Ligate DNA fragments
• Cut DNA at specific sequences
• Replicate plasmids
• Initiate transcription

Which enzyme is responsible for joining DNA fragments together?

• DNA polymerase
• RNA ligase
• DNA ligase
• Reverse transcriptase

Which feature in plasmids allows for the insertion of foreign DNA?

• Origin of replication
• Selectable marker
• Multiple cloning site
• Promoter region

Blue/white screening is used to identify:

• Cells with intact lacZ′ gene
• Ligation of foreign DNA
• Cells resistant to antibiotics
• High plasmid copy number

In transformation, we used DH5α Escherichia coli because:

• It has high competency for DNA uptake
• It produces antibiotic resistance naturally
• It synthesizes restriction enzymes
• It undergoes α-complementation

The purpose of a plasmid mini-prep is to:

• Amplify DNA fragments
• Purify plasmid DNA from bacterial cells
• Cut DNA at specific sites
• Transform competent cells

In gel electrophoresis, the gel is typically composed of:

• Agarose
• Starch
• Cellulose
• Agar

In gel electrophoresis, DNA moves through the gel because:

• DNA is positively charged
• DNA is negatively charged and moves towards the positive electrode
• DNA reacts with the gel matrix
• DNA is neutral and moves by diffusion

The purpose of a DNA ladder in gel electrophoresis is to:

• Increase the resolution of DNA bands
• Stain the DNA for visualization
• Serve as a size reference for estimating DNA fragment lengths
• Enhance DNA movement through the gel

Which of the following is used to visualize DNA bands in gel electrophoresis?

• Coomassie Blue
• RedSafe
• Silver nitrate
• Hematoxylin