Tag: pcr

Questions Related to pcr

Enzyme required for polymerase chain reaction (PCR) is

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

  1. RNA polymerase

  2. Ribonuclease

  3. Taq polymerase

  4. Endonuclease

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Correct Option: C

Thermal cycle 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. Radioactivation

  2. Chemical reaction

  3. Polymerase chain reaction

  4. Enzyme catalysed reactions

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Correct Option: C

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

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

  1. Microinjection

  2. Gene gun

  3. Disarmed pathogen vectors

  4. Polymerase chain reaction

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Correct Option: D

Polymerase chain reaction

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

  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

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Correct Option: C

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

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

  1. Denaturation

  2. Annealing

  3. Polymerisation

  4. Isolation

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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?

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

  1. $4$

  2. $32$

  3. $64$

  4. $16$

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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?

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

  1. All four DNA bases

  2. Short DNA base pairs

  3. DNA polymerase

  4. DNA library

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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?

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

  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

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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'.

Polymerisation of DNA is in

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

  1. $3' \rightarrow 5'$ direction

  2. $5' \rightarrow 3'$ direction

  3. Both $3' \rightarrow 5'$ and $5' \rightarrow 3'$ direction

  4. None of the above

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Correct Option: B
Explanation:
DNA polymerase has 5' $\rightarrow$ 3' activity. All known DNA replication systems require a free 3' hydroxyl group before synthesis can be initiated (note: the DNA temple is read in 3' to 5' direction whereas a new strand is synthesized in 5' to 3' direction).
So, the correct answer is "5' $\rightarrow$ 3' ".

In PCR, short primers are added to single stranded DNA molecules in a test tube and the appropriate enzymes are included to make a copy of the DNA. Which of the following primers is needed for copying the single stranded DNA sequence $ 5'TACGGTAGGTC3'$ ?

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

  1. $5'ATGCC 3'$

  2. $ 5'GACCT 3' $

  3. $ 3'GACCT 5' $

  4. $ 3'ATGCC 5' $

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Correct Option: A
Explanation:

A primer is a short single strand of RNA or DNA (generally about 18-22 bases) that serves as a starting point for DNA synthesis. It is required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA. The polymerase starts replication at the 3′-end of the primer, and copies the opposite strand. 


For copying the single stranded DNA sequence 5′TACGGTAGGTC3′, complementary sequence possessing primer is needed which is 5′GACCT3′.

So the correct option is '5′GACCT3′'.