NEET Biology Biotechnology Principles and Processes MCQs Set 03

Answer: (b) Biotechnology

Explanation:
1. Biotechnology deals with techniques of using live organisms or enzymes to produce products and processes useful to humans.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (a) Genus of organism

Explanation:
1. The first letter of a restriction enzyme name comes from the genus of the bacterium.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (a) Bioreactors

Explanation:
1. Large volumes of culture are processed in bioreactors.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (c) DNA ligase

Explanation:
1. DNA ligase joins DNA fragments and is called genetic glue.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (a) Primers

Explanation:
1. Primers are small chemically synthesised oligonucleotides complementary to the ends of the target DNA.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (a) Biolistics

Explanation:
1. Biolistics (gene gun) bombards gold or tungsten particles coated with DNA onto target cells.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (d) Ampicillin and tetracyclin resistant genes

Explanation:
1. pBR322 has genes for ampicillin and tetracycline resistance.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (b) Cellulase

Explanation:
1. Cellulase digests the cell wall of plant cells to release DNA.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (a) Retro viruses

Explanation:
1. In animals, normal cells are transformed into cancerous cells by retroviruses.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (d) b-galactosidase

Explanation:
1. Insertional inactivation inactivates the beta-galactosidase enzyme when foreign DNA is inserted in its gene.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (b) 42°C

Explanation:
1. Cells are made competent by a heat shock at 42 degrees Celsius after incubation on ice.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (c) Introduction of unidentified DNA into the host

Explanation:
1. Introduction of unidentified DNA into the host is not a basic step in genetic modification; the DNA must be identified first.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (a) Stanley cohen and Herbert Boyer

Explanation:
1. Stanley Cohen and Herbert Boyer constructed the first recombinant DNA.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (b) 5'-GAATTC-3' / 3'-CTTAAG-5'

Explanation:
1. EcoRI cuts the palindromic sequence GAATTC between G and A on each strand.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (d) Restriction endonuclease

Explanation:
1. The enzymes isolated in 1963 that restricted bacteriophage growth in E. coli were restriction endonuclease and a methylase.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (a) Paul Berg

Explanation:
1. Paul Berg is regarded as the father of genetic engineering for making the first recombinant DNA molecule.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (c) European Federation of Biotechnology

Explanation:
1. The European Federation of Biotechnology gave the definition covering both traditional and modern views.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (b) Thermus aquaticus

Explanation:
1. Taq polymerase is obtained from the thermophilic bacterium Thermus aquaticus.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (d) 94°C

Explanation:
1. The template DNA is denatured by heating to about 94 degrees Celsius in PCR.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (a) The order in which the enzymes were isolated from that strain of bacteria

Explanation:
1. The Roman numerals indicate the order in which enzymes were isolated from a bacterial strain.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (b) Ability to produce colour in the presence of a chromogenic substrate

Explanation:
1. Alternative selectable markers use ability to produce colour in the presence of a chromogenic substrate.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (d) Hind II

Explanation:
1. Hind II was the first restriction endonuclease to be isolated.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (b) Two selectable markers

Explanation:
1. pBR322 has two selectable markers, ampicillin and tetracycline resistance genes.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).

Answer: (c) Ribonuclease

Explanation:
1. Ribonuclease treatment removes RNA when DNA is isolated.

Teacher's Note:
1. Recombinant DNA technology tools: restriction enzymes (molecular scissors, cut at palindromic sites), DNA ligase (joins fragments), cloning vectors (plasmids with ori, selectable markers and cloning sites) and competent host cells.
2. Names of restriction enzymes: first letter from genus, next two from species, then strain and Roman numeral for order of isolation (EcoRI from Escherichia coli RY13).

Answer: (a) Non-recombinants will give blue coloured colonies in presence of chromogenic substrate

Explanation:
1. When DNA is inserted in the beta-galactosidase gene, recombinants are colourless and non-recombinants give blue colonies.

Teacher's Note:
1. PCR needs a DNA template, two primers, dNTPs and thermostable Taq polymerase (from Thermus aquaticus), with cycles of denaturation (about 94 C), annealing and extension.
2. Gel electrophoresis separates negatively charged DNA towards the anode through agarose, by size (sieving effect); bands are seen with ethidium bromide under UV and cut out for elution.

Answer: (b) Restriction endonuclease

Explanation:
1. Restriction endonucleases cut DNA at specific sites, so they are called molecular scissors (knives) of DNA.

Teacher's Note:
1. Insertional inactivation of beta-galactosidase lets recombinants be recognised as colourless colonies, whereas non-recombinants give blue colonies with a chromogenic substrate.
2. Delivery methods: heat shock, microinjection (animal cells), biolistics or gene gun (plants) and disarmed Ti plasmid of Agrobacterium (dicots).