Tag: pcr

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Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

Polymerase chain reaction employs

  1. Primers and DNA ligase

  2. DNA ligase only

  3. DNA polymerase only

  4. Primers and DNA polymerase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

PCR requires primers to define the target region and a DNA polymerase to extend the strands. DNA ligase is not used in PCR.

Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

PCR proceeds in three distinct steps governed by temperature. The order of the steps is 

  1. Denaturation, Synthesis, Annealing

  2. Annealing, Synthesis, Denaturation

  3. Synthesis, Annealing, Denaturation

  4. Denaturation, Annealing, Synthesis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The three steps of PCR are: 1) Denaturation (high heat to separate strands), 2) Annealing (cooling to allow primers to bind), and 3) Extension/Synthesis (optimal temperature for polymerase to build the new strand).

Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

What is true about DNA polymerase used in PCR?

  1. It is used to ligate introduced DNA in recipient cells.

  2. It serves as selectable marker.

  3. It is isolated from a virus.

  4. It is active at high temperature.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The DNA polymerase used in PCR (like Taq) is derived from thermophilic bacteria, making it heat-stable and capable of remaining active through the repeated high-temperature denaturation cycles.

Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

Melting of DNA at 70$^o$ C is due to breakdown of

  1. Phosphodiester bonds

  2. Hydrogen bonds

  3. Glycosidic bonds

  4. Disulphide bonds
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DNA denaturation involves the separation of the two strands of the double helix. This process is driven by the breaking of hydrogen bonds between complementary nitrogenous bases.

Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

Amplification of gene of interest by using PCR may go upto

  1. 0.1 million

  2. 1.0 million

  3. 1.0 billion

  4. 1.0 trillion
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

PCR is a powerful technique for amplifying DNA sequences. Through repeated cycles of denaturation, annealing, and extension, a single DNA molecule can be amplified to approximately 1 billion copies.

Multiple choice bio-chemistry applications of biotechnology pcr cutting, insertion and ligation of dna gene cloning procedure biotechnological regulations asexual modes of reproduction

At which temperature a DNA molecule is denatured by heat in PCR

  1. 70$^o$ - 80$^o$C
  2. 90$^o$ - 95$^o$C
  3. 42$^o$C
  4. 50$^o$ - 65$^o$C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the PCR process, the denaturation step requires high temperatures to break the hydrogen bonds between DNA strands. This typically occurs between 90 and 95 degrees Celsius.