1) Taq Polymerase is a commonly used DNA polymerase in a PCR Reaction? T/F
True: Other thermostable DNA polymerases can also be used such as “Pfu polymerase” which has a lower error rate when generating DNA strands.
2) DNA melting involves disrupting the covalent bonds between complementary DNA sequences? T/F
False: DNA melting refers to the disrupting of hydrogen bonds between complementary DNA sequences.
3) Annealing of the primers occurs at the temperature of 50-65C? T/F
True: Annealing temperature usually 3-5 degrees below the melting temperature of the prinmers used.
4) Primers generally consist of 200-300 nucleotides? T/F
False: Primers usually consist of approximately 20 nucleotides.
5) In a PCR reaction, the DNA generated is itself used as a template for replication? T/F
True: This is the whole reason and concept behind the exponential increase in target DNA strand.
6) Primers all have the same melting temperature? T/F
False: Melting temperature of DNA strands, (including primers) dependent to some extent on the amount of Guanosine-Cytosine (GC) bonds, which generally have stronger bonds than Adenosine-Thymine (AT). Thus primers with higher GC content have higher melting temperatures.
7) The melting temperature is the temperature at which the DNA disintegrates into it’s separate nucleotides? T/F
False: It is the temperature at which complementary DNA strands separate.
8) Urea may assist DNA denaturation? T/F
9) The extension step usually occurs at a lower temperature than the annealing step? T/F
False: The temperature in the PCR reaction is usually increased slightly to optimise this step.
10) PCR was invented by Sir Francis Crick?
False: Crick involved with discovering the Double Helix structure of DNA. Discovery of PCR attributed to Kary Mullis in 1983.
3 thoughts on “MCQs: The Basic PCR Reaction: Answers”
Very Useful for teaching at the undergrad level. More of these will be appreciated
I will see what I can do Naiyyum!
useful for basic knowledge