State the Role of DNA Ligase in Biotechnology. - Biology


State the role of DNA ligase in biotechnology.



DNA ligase enzyme is used to join two DNA fragments from their ends.

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2011-2012 (March) Delhi Set 1


Retroviruses have no DNA. However, the DNA of the infected host cell does possess viral DNA. How is it possible?

Explain the work carried out by Cohen and Boyer that contributed immensely in biotechnology.

Name the genes responsible for making Bt cotton plants resistant to bollworm attack. How do such plants attain resistance against bollworm attacks? Explain.

distinguish between Plasmid DNA and chromosomal DNA

What does PCR stand for? Describe the different steps of PCR

Give an account of the Blue-White Method of selection of recombinants

Name the most commonly used bioreactor and describe its working.

One of the major contributions of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.



Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.

Write a short note on Electrophoresis.

Give one significant difference between:

Electroporation and Gene Gun.

Explain the mechanism of action of restriction endonucleases that makes them suitable for genetic engineering.

Explain what are the desirable characteristics of an ideal cloning vector used in rDNA technology.

Give a reason why :
Proteases are added during the isolation of DNA for genetic engineering.

The bacterium which causes a plant disease called crown gall is _______________.

The enzyme nuclease hydrolyses ______ of polynucleotide chain of DNA.

Enlist different types of restriction enzymes commonly used in rDNA technology? Write about their role.

Enlist and write in brief about the different biological tools required in rDNA technology.

The enzyme restriction endonuclease ______.

What is Palindromic sequence?

Bt-cotton shows adverse effect on the population of which butterfly?

Identify the characters that a cloning vector should possess.

i. Origin of replication (Ori)

ii. Ability to destroy the alien DNA

ii. Cloning site to link the alien DNA

iv. The tumour inducing plasmid Ti

v. Selectable marker

vi. Low molecular weight

DNA polymerase enzyme used in PCR is isolated from ____________ bacteria.

The time taken to complete one cycle of PCR is around ______.

From the following identify the methods of electrophoresis.

Which of the following device is required for PCR?

The following identifies the major features of technology that differentiate modem biotechnology from classical biotechnology.

i. Capability of science to change the genetic material for getting new specific products through rDNA technology, polymerase chain reaction (PCR), microarrays, cell culture and fusion, and bioprocessing.

ii. Ownership of technology and its sociopolitical impact.

iii. Modem biotechnology makes use of only fermentation technology.

iv. Classical biotechnology relies only on principles of plant and animal tissue culture. 

____________ cuts the DNA within the specific positions.

Identify the CORRECT order of steps in Polymerase Chain Reaction (PCR).

The gene transfer between unrelated plants is brought about by ____________.

Lytic cycle involves bacteriophage and ____________.

Name and describe the technique that helps in separation of DNA fragments.

Which of the following statements is correct with respect to cellular respiration?

Which of the following viruses has the capacity to produce lysozymes?

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

The source of taq Polymerase used in PCR is a ______.

A hind of biotechnology involving manipulation of DNA is ______.

What is true for plasmid?

Nucleic acid segment tagged with a radioactive molecule is called ______.

DNA fingerprinting refers to ______.

The transfer of genetic material from one bacterium to another through the mediation of a viral vector is termed as ______.

What is the significance of adding proteases at the time of isolation of genetic material (DNA)?

Name a recombinant vaccine that is currently being used in vaccination program?

A recombinant DNA molecule was created by ligating a gene to a plasmid vector. By mistake, an exonuclease was added to the tube containing the recombinant DNA. How does this affect the next step in the experiment i.e. bacterial transformation?

What would happen when one grows a recombinant bacterium in a bioreactor but forget to add antibiotic to the medium in which the recombinant is growing?

Annealing step of PCR operates at ______ °C.

Which of the following is the correct recognition sequence of restriction enzyme Eco RI?

Observe the given sequence of nitrogenous bases on a DNA fragments and answer the following questions:


  1. Name a restriction enzyme which can recognise this DNA sequence.
  2. Write the sequence after digestion.
  3. Why are the ends generated after digestion called sticky ends?

Which vector is mostly used in rDNA technology in plants?

Name two restriction enzymes used in PCR.

The given figure is the diagrammatic representation of the E. coli vector pBR322. Which one of the given options correctly indentites its certain component(s)?

What is polymerase chain reaction (PCR)?

How gene amplification is done?

Tissue plasminogen activator and urokinase are used in the treatment of ______.

Name the enzymes that are called molecular scissors.

In vitro amplification of DNA segments is called______.

Name the source of thermostable DNA polymerase.

How many sets of primers are required in each cycle of PCR?

Study the diagram given below and answer the questions that follow.

  1. Name the cloning vector shown above. In which organism in this cloning vector inserted?
  2. Mention any two restriction sites shown in the diagram.

  3. Name any two selectable markers shown in the diagram.


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