Chapter 11 – Biotechnology : Principles And Processes

Rising of dough is due to:

• a.Multiplication of yeast
• b.Production of CO2
• c.Emulsification
• d.Hydrolysis of wheat flour starch into sugars.

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

• a.endonuclease
• b.exonuclease
• c.DNA ligase
• d.Hind - II

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

• a.Transduction
• b.Conjugation
• c.Transformation
• d.Translation

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

• a.DNA can be seen in visible light
• b.DNA can be seen without staining in visible light
• c.Ethidium bromide stained DNA can be seen in visible light
• d.Ethidium bromide stained DNA can be seen under exposure to UV light

'Restriction' in Restriction enzyme refers to:

• a.Cleaving of phosphodiester bond in DNA by the enzyme
• b.Cutting of DNA at specific position only
• c.Prevention of the multiplication of bacteriophage by the host bacteria
• d.All of the above

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

• a.Restriction endonuclease
• b.DNA ligase
• c.DNA fragments
• d.E.coli

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

• a.Charge only
• b.Size only
• c.Charge to size ratio
• d.All of the above

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

• a.Origin of replication (ori)
• b.Presence of a selectable marker
• c.Presence of sites for restriction endonuclease
• d.Its size

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

• a.Lysozyme
• b.Ribonuclease
• c.Deoxyribonuclease
• d.Protease

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

• a.Easy availability of DNA template
• b.Availability of synthetic primers
• c.Availability of cheap deoxyribonucleotides
• d.Availability of 'Thermostable' DNA polymerase BIOTECHNOLOGY PRINCIPLES AND PROCESSES 77

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

• a.Competent bacterial cells
• b.Transformed bacterial cells
• c.Recombinant bacterial cells
• d.None of the above

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

• a.Binding of DNA to the cell wall
• b.Uptake of DNA through membrane transport proteins
• c.Uptake of DNA through transient pores in the bacterial cell wall
• d.Expression of antibiotic resistance gene

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

• a.Formation of phosphodiester bond between two DNA fragments
• b.Formation of hydrogen bonds between sticky ends of DNA fragments
• c.Ligation of all purime and pyrimidine bases
• d.None of the above

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

• a.Haemophilus influenzae
• b.Escherichia coli
• c.Entamoeba coli
• d.Bacillus amyloliquefaciens

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

• a.Denaturation of template DNA
• b.Annealing of primers to template DNA
• c.Extension of primer end on the template DNA
• d.All of the above

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:

• a.Human gene may have intron which bacteria cannot process
• b.Amino acid codons for humans and bacteria are different
• c.Human protein is formed but degraded by bacteria
• d.All of the above

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

• a.Laboratory flask of largest capacity
• b.A stirred-tank bioreactor without in-lets and out-lets
• c.A continuous culture system
• d.Any of the above

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

• a.Herbert Boyer
• b.Hargovind Khurana
• c.Kary Mullis
• d.Arthur Kornberg

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

• a.It recognises a palindromic nucleotide sequence
• b.It is an endonuclease
• c.It is isolated from viruses
• d.It can produce the same kind of sticky ends in different DNA molecules