Tag: cutting, insertion and ligation of dna

Questions Related to cutting, insertion and ligation of dna

The taq polymerase enzyme is obtained from

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

  1. Thiobacillus ferroxidans

  2. Bacillus subtilis

  3. Pseudomonas putida

  4. Thermus aquaticus

Show answer
Correct Option: D
Explanation:
Taq polymerase is a thermostable DNA polymerase named after the thermophilic bacterium Thermus aquaticus from which it was originally isolated by Chien et al. in 1976. Its name is often abbreviated to Taq Pol or simply Taq. It is frequently used in the polymerase chain reaction (PCR), a method for greatly amplifying the quantity of short segments of DNA.

T. aquaticus is a bacterium that lives in hot springs and hydrothermal vents, and Taq polymerase was identified as an enzyme able to withstand the protein-denaturing conditions (high temperature) required during PCR. Therefore, it replaced the DNA polymerase from E. coli originally used in PCR. Taq's optimum temperature for activity is 75–80 °C, with a half-life of greater than 2 hours at 92.5 °C, 40 minutes at 95 °C and 9 minutes at 97.5 °C, and can replicate a 1000 base pair strand of DNA in less than 10 seconds at 72 °C.

So the correct option is 'Thermus aquaticus'.

Which one is a true statement regarding $DNA$ polymerase used in $PCR$

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

  1. it is used to ligate introduced $DNA$ in recipient cell

  2. it serves as a selectable marker

  3. it is isolated from a virus

  4. it remains active at high temperature

Show answer
Correct Option: D
Explanation:
Taq polymerase is a thermostable DNA polymerase named after the thermophilic bacterium Thermus aquaticus from which it was originally isolated by Chien et al. in 1976. Its name is often abbreviated to Taq Pol or simply Taq. It is frequently used in the polymerase chain reaction (PCR), a method for greatly amplifying the quantity of short segments of DNA.

T. aquaticus is a bacterium that lives in hot springs and hydrothermal vents, and Taq polymerase was identified as an enzyme able to withstand the protein-denaturing conditions (high temperature) required during PCR. Therefore, it replaced the DNA polymerase from E. coli originally used in PCR. Taq's optimum temperature for activity is 75–80 °C, with a half-life of greater than 2 hours at 92.5 °C, 40 minutes at 95 °C and 9 minutes at 97.5 °C, and can replicate a 1000 base pair strand of DNA in less than 10 seconds at 72 °C.

So the correct option is 'it remains active at high temperature'.

Which of the following steps is/are catalysed by Taq polymerase in a PCR?

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

  1. Denaturation of template DNA

  2. Annealing of primers to template DNA

  3. Extension of primer end on template DNA

  4. All of these

Show answer
Correct Option: C
Explanation:

PCR is the short form for polymerase chain reaction which is the phenomenon which is used for amplification of the part-specific region of DNA as per our interest. Taq polymerase is the enzyme that attaches nucleotides together and help is the extension of primer end on the template DNA.

So, the correct answer is 'extension of primer end on the template DNA'.

Which among the following is true for protein synthesis in bacteria?

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

  1. It involves all the three types of RNAs (m-RNA, t-RNA and r-RNA)

  2. It involves $3$ types of RNA polymerase

  3. It involves single type of RNA polymerase

  4. It involves RNA processing

Show answer
Correct Option: C

Select the wrong pair

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

  1. RNA polymerase I - Sn RNA 5S rRNA, r-RNA

  2. RNA polymerase I - r-RNA

  3. RNA polymerase II - hnRNA

  4. RNA polymerase III - tRNA

Show answer
Correct Option: A

Taq polymerase enzyme is used in

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

  1. Restriction mapping

  2. Gene cloning

  3. PCR

  4. All of the above

Show answer
Correct Option: C
Explanation:

Taq polymerase is a heat stable enzyme used in the polymerase chain reaction (PCR) to amplify segments of DNA in the lab. 

Thus, the correct answer is option C.

Which of the following would not be a valid reason to use PCR?

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

  1. Help in analyzing DNA of ancient remains of fossilized woolly mammoth

  2. Help in analyzing the genome of a virus

  3. Help in determining the DNA of a hair sample found at a crime scene

  4. Help in transferring DNA from a plasmid containing GFP into E.coli

Show answer
Correct Option: D
Explanation:

Majorly the PCR is used in analyzing and determining purposes only not the transferring purposes. For transferring purpose vectors are used. In analyzing and determining purposes, the sample is limited i.e. if the sample gets destroyed no analysis can be carried out which can be a big problem in the investigation cases. So to have extra copies of the sample it is first amplified by PCR.

Thermal cycler is used in one of these reactions.

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

  1. Radioactivity

  2. Enzyme catalysed reaction

  3. Chemical reaction

  4. Polymerase chain reaction

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Correct Option: A

DNA polymerase required for synthesizing copies of DNA at high temperature is obtained from

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

  1. Thermus aquaticus

  2. Cephalosporium minimum

  3. Bacillus megaterium

  4. Thermoproteus species

Show answer
Correct Option: A
Explanation:

A. Thermus aquaticus is a thermophilic bacteria which survives at high temperatures. Thus it's DNA polymerase is evolved to synthesize DNA at high temperature. This DNA polymerase is commercially available as "Taq polymerase" and is used in polymerase chain reaction (PCR).

B. Cephalosporium minimum is a plant pathogen and are producers of antibiotic cephalosporin.
C. Bacillus megaterium is a soil bacteria whose DNA polymerase is not thermo resistant. Hence it cannot synthesize DNA at high temperatures.
D. Thermoproteus species are sulphur utilizing hyperthermophiles which grow is acidic hot springs. Such bacteria are difficult to grow in lab conditions. Although its DNA polymerase can synthesize DNA at high temperatures, due to inability to grow in lab conditions, its DNA polymerase cannot be obtained.
Hence the correct answer is 'Thermus aquaticus'

Which of the following techniques is used to make numerous copies of a specific segment of DNA quickly and accurately?

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

  1. Translation

  2. Transcription

  3. Polymerase chain reaction

  4. Ligase chain reaction

Show answer
Correct Option: C
Explanation:

For making numerous copies of a specific segment of DNA three steps are required

1.Denaturing
2.Annealing
3.Extending
Which is called a polymerase reaction.
So, the correct option is 'Polymerase chain reaction'.