Tag: biotechnological regulations

Questions Related to biotechnological regulations

DNA taq polymerase enzyme is isolated from which bacteria?

  1. Agrobacterium

  2. Thermus aquaticus

  3. Bacillus thuringiensis

  4. E.coli


Correct Option: B
Explanation:

DNA polymerase enzyme was isolated from a thermophilc bacteria called Thermus aquaticus. This is an enzyme used frequently to make multiple copies of segment of DNA by a technique called polymerase chain reaction.

The whole cycle of gene amplification requires

  1. 15 minutes

  2. 30 minutes

  3. 3 hours

  4. 24 hours.


Correct Option: B
Explanation:

The denaturation stage of PCR takes about 1–2 minutes. The thermocycler then lowers the temperature to about 50° to 60°C, which allows the short, oligonucleotide primers to anneal to their complementary sequences on the single-stranded DNA molecules. The annealing stage of PCR lasts about 30 seconds. Hence, the whole cycle of gene amplification requires 30 minutes.

So, the correct answer is '30 minutes.'

Enzyme required for polymerase chain reaction (PCR) is

  1. RNA polymerase

  2. Ribonuclease

  3. Taq polymerase

  4. Endonuclease


Correct Option: C

Thermal cycle is used in

  1. Radioactivation

  2. Chemical reaction

  3. Polymerase chain reaction

  4. Enzyme catalysed reactions


Correct Option: C

One of the methods of which DNA cannot be transferred to the host cell is by

  1. Microinjection

  2. Gene gun

  3. Disarmed pathogen vectors

  4. Polymerase chain reaction


Correct Option: D

Polymerase chain reaction

  1. Is a method of synthesising human protein from human DNA

  2. Uses restriction enzymes

  3. Can produce billions of copies of a DNA fragment

  4. Takes place naturally in bacteria


Correct Option: C

During PCR technique the pairing of primers to ssDNA segment is called

  1. Denaturation

  2. Annealing

  3. Polymerisation

  4. Isolation


Correct Option: B
Explanation:
PCR - technique amplify the DNA sample in three steps namely denaturation of target DNA, annealing and polymerization. Denaturation refers to the thermal cycle that separates the DNA strands and forms the ssDNA. Annealing refers to the pairing of primers to the ssDNA and polymerisation is the extension of primer into complete DNA strand complementary to the template strand. 
So, the correct answer is 'Annealing'

How many copies of the DNA sample are produced in PCR technique after 6-cycle?

  1. $4$

  2. $32$

  3. $64$

  4. $16$


Correct Option: C
Explanation:

Polymerase chain reaction (PCR) is a technique that exponentially amplifies a single copy of a specific DNA segment. It generates thousands of copies of that specific DNA segment. After completion of one cycle, 2 copies are produced from a single DNA segment. After completion of the second cycle, 2$^2$ = 4 copies are produced. Similarly, after n$^{th}$ cycle, 2$^2$ copies are produced, where n is the number of cycles. Hence, after completion of 6 cycle, 2$^6$ = 64 copies will be produced. 

Thus, the correct answer is '64.'

Which of the following is not necessary to execute polymerase chain reaction successfully?

  1. All four DNA bases

  2. Short DNA base pairs

  3. DNA polymerase

  4. DNA library


Correct Option: D
Explanation:

Polymerase Chain Reaction (PCR) is widely used the method in genetic engineering to prepare the multiple copies of desired DNA. It includes steps of denaturation, annealing extension and last amplification. As DNA is the polymer of four DNA bases present in the base pair and polymerase chain reaction is done in the presence of DNA polymerase enzyme of the DNA that re-studies by the researchers which is said to be DNA library so it is not required in the reaction.

So the correct option is 'DNA library'.

In reference to DNA polymerase III, which statement is wrong?

  1. It requires ATP For polymerase action.

  2. Required for PCR

  3. More active than DNA Pol I & II

  4. Requires a previously made template to work on


Correct Option: B
Explanation:
Like DNA replication in an organism, PCR requires a DNA polymerase enzyme that makes new strands of DNA, using existing strands as templates. The DNA polymerase typically used in PCR is called Taq polymerase, after the heat-tolerant bacterium from which it was isolated (Thermus aquaticus).
So, the correct option is 'Required for PCR'.