NCERT Exemplar solutions for Biology [English] Class 12 chapter 11 - Biotechnology : Principles and Processes [Latest edition]

Rising of dough is due to ______.

Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?

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

Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?

'Restriction' in Restriction enzyme refers to ______.

Which of the following is not required in the preparation of a recombinant DNA molecule?

In agarose gel electrophoresis, DNA molecules are separated on the basis of their ______.

The most important feature in a plasmid to serve as a vector in gene cloning experiment is ______.

While isolating DNA from bacteria, which of the following enzymes is not required?

Which of the following contributed in popularising the PCR (polymerase chain reactions) technique?

An antibiotic resistance gene in a vector usually helps in the selection of ______.

Significance of 'heat shock' method in bacterial transformation is to facilitate ______.

The role of DNA ligase in the construction of a recombinant DNA molecule is ______.

Which of the following bacteria is not a source of restriction endonuclease?

Which of the following steps are catalysed by Taq DNA polymerase in a PCR reaction?

A bacterial cell was transformed with a recombinant DNA molecule that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be ______.

Which of the following should be chosen for best yield if one were to produce a recombinant protein in large amounts?

Who among the following was awarded the Nobel Prize for the development of PCR technique?

Which of the following statements does not hold true for restriction enzyme?

How is copy number of the plasmid vector related to yield of recombinant protein?

Would you choose an exonuclease while producing a recombinant DNA molecule?

What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?

Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.

What does ‘competent’ refer to in competent cells used in transformation experiments?

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

While doing a PCR, ‘denaturation’ step is missed. What will be its effect on the process?

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

Do biomolecules (DNA, protein) exhibit biological activity in anhydrous conditions?

What modification is done on the Ti plasmid of Agrobacterium tumefaciens to convert it into a cloning vector?

What is meant by gene cloning?

Both a wine maker and a molecular biologist who had developed a recombinant vaccine claim to be biotechnologists. Who in your opinion is correct?

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?

Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at ‘specific-recognition sequence’. What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?

A plasmid DNA and a linear DNA (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.

How does one visualise DNA on an agarose gel?

A plasmid without a selectable marker was chosen as vector for cloning a gene. How does this affect the experiment?

A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?

Describe the role of CaCl₂ in the preparation of competent cells?

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?

Identify and explain steps ‘A’, ‘B’ and ‘C’ in the PCR diagram given below.

Name the regions marked A, B and C.

For selection of recombinants, insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate. Give reasons.

Describe the role of Agrobacterium tumefaciens in transforming a plant cell.

Illustrate the design of a bioreactor. Highlight the difference between a flask in your laboratory and a bioreactor which allows cells to grow in a continuous culture system.