The separation of DNA fragments in gel electrophoresis is achieved through a sieving effect provided by the _________ gel.

[Biotechnology-Principles-and-Processes] [class-xii ]

• agarose
• cellulose
• polypropylene
• polyacrylamide
Correct Option: A  [ agarose ]

Remark: DNA fragments separate through sieving effect provided by the agarose gel.

When recombinant DNA is transferred into *E. coli*, it could replicate using the new host’s DNA polymerase enzyme and make multiple copies because it is a circular autonomously replicating DNA created _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• in vivo
• in situ
• in vitro
• in silico
Correct Option: C  [ in vitro ]

Remark: Recombinant DNA is a circular autonomously replicating DNA created in vitro.

The DNA is cut with restriction enzymes after it is isolated in a pure form, free from other macromolecules like RNA, proteins, polysaccharides and _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• vitamins
• lipids
• salts
• minerals
Correct Option: B  [ lipids ]

Remark: The purified DNA must be free from lipids and other macromolecules.

The ability of sexual reproduction to provide opportunities for variations is advantageous over asexual reproduction, which primarily preserves the genetic _________.

[Biotechnology-Principles-and-Processes] [class-xii ]

• mutations
• information
• sequences
• traits
Correct Option: B  [ information ]

Remark: Asexual reproduction preserves the genetic information.

The approach to understanding natural phenomena, especially natural sciences, became anthropocentric ever since the days of which philosopher?

[Biotechnology-Principles-and-Processes] [class-xii ]

• Aristotle
• Rene Descartes
• Louis Pasteur
• Stanley Cohen
Correct Option: B  [ Rene Descartes ]

Remark: Rene Descartes, the French philosopher, influenced the whole approach to understanding natural phenomena to become anthropocentric.

Herbert Boyer completed his graduate work in 1963 at which university?

[Biotechnology-Principles-and-Processes] [class-xii ]

• Stanford
• Yale
• University of California, San Francisco
• University of Pittsburgh
Correct Option: D  [ University of Pittsburgh ]

Remark: Herbert Boyer completed graduate work at the University of Pittsburgh, in 1963.

In 1966, Herbert Boyer took over an assistant professorship at which institution?

[Biotechnology-Principles-and-Processes] [class-xii ]

• Yale University
• University of California at San Francisco
• Stanford University
• University of Pittsburgh
Correct Option: B  [ University of California at San Francisco ]

Remark: Boyer took over assistant professorship at the University of California at San Francisco in 1966.

Herbert Boyer performed studies on restriction enzymes of which specific bacterium in 1969?

[Biotechnology-Principles-and-Processes] [class-xii ]

• Salmonella typhimurium
• E. coli
• Agrobacterium tumifaciens
• Thermus aquaticus
Correct Option: B  [ E. coli ]

Remark: Boyer performed studies on restriction enzymes of the E. coli bacterium in 1969.

What term is used for the overhanging stretches left on DNA strands after restriction enzymes cut them in a particular fashion?

[Biotechnology-Principles-and-Processes] [class-xii ]

• Blunt ends
• Sticky ends
• Palindromic sequences
• Recognition sequences
Correct Option: B  [ Sticky ends ]

Remark: The enzymes left ‘sticky ends’ on the DNA strands, which made pasting pieces of DNA precise.

Stanley Cohen studied small ringlets of DNA that float freely in the cytoplasm of certain bacterial cells and replicate independently, known as:

[Biotechnology-Principles-and-Processes] [class-xii ]

• Nucleoids
• Chromosomes
• Plasmids
• Ribosomes
Correct Option: C  [ Plasmids ]

Remark: Cohen had been studying small ringlets of DNA called plasmids that replicate independently.