Lab Quiz #3: PCR

The reason for using Taq polymerase for PCR is that _____.

• it is heat stable and can withstand the heating step of PCR

• only minute amounts are needed for each cycle of PCR

• it binds more readily than other polymerases to the primers

• it has regions that are complementary to the primers

What information is critical to the success of polymerase chain reaction (PCR) itself?

• The sequence of restriction-enzyme recognition sites in the DNA to be amplified must be known.

• The DNA sequence of the ends of the DNA to be amplified must be known.

• The complete DNA sequence of the DNA to be amplified must be known.

• The sequence of restriction-enzyme recognition sites in the DNA to be amplified and in the plasmid where the amplified DNA fragment will be cloned must be known.

Which of the following is in the correct order for one cycle of polymerase chain reaction (PCR)?

• Extend primers; anneal primers; denature DNA.

• Denature DNA; anneal primers; extend primers.

• Anneal primers; denature DNA; extend primers.

• Denature DNA; add fresh enzyme; anneal primers; add dNTPs; extend primers

The heat stable DNA polymerase that performs the polymerization was isolated from a __________ bacterium.

• Thermophilic
• Psychrophile

• Halophile

• Acidophilic

Assume you are performing a 22 PCR cycle reaction to amplify your DNA insert. How many copies of DNA will you have at the end of your PCR?

• 4,194,304

• 4,800,000

• 1,048,576

• 2,097,152

DNA migrates toward the positive electrode because

• DNA is negatively charged

• DNA's backbone is negatively charged

• DNA’s backbone is negatively charged due to phosphate groups

• DNA is negatively charged due its nitrogenous bases

The rate of migration of DNA during electrophoresis is based on what factor?

• Negative charge of DNA fragments

• Number of DNA fragments

• Size of DNA fragments

• Volume of DNA fragments

The higher the concentration of agarose, the smaller is the pore size of the gel and it takes _____.

• more time for large molecules to move

• less time for small molecules to move

• more time for small molecules to move

• less time for large molecules to move

What is the function of a DNA ladder?

• to estimate the total charges of the DNA strands

• to estimate the size of the DNA strands

• to estimate the orientation of the DNA strands

• to estimate the length of the DNA strands

What enzyme in DNA replication is equivalent to heat in a PCR?

• Helicase

• Polymerase I

• Ligase

• Polymerase III