To maintain the cells in their physiologically most active log/exponential phase during continuous culture, the used medium is drained out from one side while _________ medium is added from the other.

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

• sterile
• fresh
• pre-heated
• waste
Correct Option: B  [ fresh ]

Remark: Fresh medium is added to maintain the active log/exponential phase.

A plasmid used as a cloning vector is an autonomously replicating circular _________ DNA.

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

• linear
• extra-chromosomal
• nuclear
• viral
Correct Option: B  [ extra-chromosomal ]

Remark: A plasmid is an autonomously replicating circular extra-chromosomal DNA.

The basic utility of the biological world recognized in human knowledge is as a source of _________.

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

• shelter
• food
• energy
• medicine
Correct Option: B  [ food ]

Remark: The major utility of the biological world is as a source of food.

Biotechnology deals with techniques of using live organisms or _________ from organisms to produce products and processes useful to humans.

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

• cells
• biomaterials
• enzymes
• proteins
Correct Option: C  [ enzymes ]

Remark: Biotechnology deals with techniques of using live organisms or enzymes from organisms.

Synthesising a gene, developing a DNA vaccine or correcting a defective gene, are all processes included under _________.

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

• bioprocess engineering
• in vitro fertilisation
• biotechnology
• traditional hybridization
Correct Option: C  [ biotechnology ]

Remark: These specific molecular techniques are explicitly listed as part of biotechnology.

For the multiplication of any alien piece of DNA in an organism, it needs to be linked with the _________.

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

• vector DNA
• origin of replication
• selectable marker
• restriction site
Correct Option: B  [ origin of replication ]

Remark: Alien DNA must be linked with the origin of replication to multiply.

If foreign DNA is inserted into the *ampR* gene of pBR322, the recombinants would lose ampicillin resistance but could be selected out from non-recombinant ones by plating on medium containing _________ first.

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

• tetracycline
• kanamycin
• ampicillin
• chloramphenicol
Correct Option: C  [ ampicillin ]

Remark: The transformants must first be selected on the medium containing the antibiotic for which the resistance gene is intact.

Bioreactors provide optimal conditions for achieving the desired product by providing optimum growth conditions (temperature, pH, substrate, salts, vitamins, _________).

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

• pressure
• density
• oxygen
• UV light
Correct Option: C  [ oxygen ]

Remark: Oxygen is listed as an optimum growth condition provided by a bioreactor.

In the selection based on $\beta$-galactosidase insertion, colonies that do not produce any colour are identified as _________ colonies.

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

• non-transformant
• mutant
• recombinant
• blue
Correct Option: C  [ recombinant ]

Remark: No colour means insertional inactivation occurred, identifying them as recombinant colonies.

The tumor inducing (Ti) plasmid of *Agrobacterium tumifaciens* has been modified into a cloning vector which is no longer _________ to the plants.

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

• hydrophilic
• pathogenic
• competent
• dependent
Correct Option: B  [ pathogenic ]

Remark: The Ti plasmid has been modified so it is no longer pathogenic.