In downstream processing, which critical step is required for formulations intended as drugs?

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

• Fragmentation of DNA
• Ligation of products
• Clinical trials
• DNA purification
Correct Option: C  [ Clinical trials ]

Remark: Formulations intended as drugs must undergo thorough clinical trials.

Asexual reproduction differs fundamentally from sexual reproduction in that it primarily:

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

• Creates variations
• Preserves the genetic information
• Allows introduction of foreign genes
• Requires a selectable marker
Correct Option: B  [ Preserves the genetic information ]

Remark: Asexual reproduction preserves the genetic information, while sexual reproduction permits variation.

To maintain the cells in the active log/exponential phase during continuous culture, what is done with the medium?

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

• The used medium is recycled entirely
• The used medium is drained out while fresh medium is added
• Only antibiotics are added periodically
• The medium is heated to 42°C repeatedly
Correct Option: B  [ The used medium is drained out while fresh medium is added ]

Remark: The used medium is drained out from one side while fresh medium is added from the other to maintain the cells in their active phase.

A plasmid used as a cloning vector is characterized as a circular autonomously replicating:

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

• Linear DNA
• Extra-chromosomal DNA
• Nuclear DNA
• Viral DNA
Correct Option: B  [ Extra-chromosomal DNA ]

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

Synthesising a gene, developing a DNA vaccine, or correcting a defective gene are all examples included under the scope of:

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

• Traditional hybridization
• In vitro fertilisation
• Biotechnology
• Bioprocess engineering
Correct Option: C  [ Biotechnology ]

Remark: These specialized techniques are included under biotechnology.

For the multiplication of any alien piece of DNA in an organism, it needs to be linked with which specific vector sequence?

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

• Selectable marker
• Origin of replication
• Restriction site
• Promoter sequence
Correct Option: B  [ Origin of replication ]

Remark: Alien DNA needs to be linked with the origin of replication to replicate and multiply itself in the host.

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

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

• Non-transformant colonies
• Mutant colonies
• Recombinant colonies
• Blue colonies
Correct Option: C  [ Recombinant colonies ]

Remark: Colourless colonies result from insertional inactivation, identifying them as recombinant colonies.

The separation of DNA fragments in gel electrophoresis is achieved due to the sieving effect provided by the:

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

• DNA polymerase
• Agarose gel
• Ethidium bromide stain
• Electric field strength
Correct Option: B  [ Agarose gel ]

Remark: The DNA fragments separate (resolve) according to their size through sieving effect provided by the agarose gel.

The first part of the modern definition of biotechnology encompasses the integration of natural science and organisms, cells, parts thereof, and:

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

• Chemical analogues
• Molecular analogues
• Synthetic polymers
• Biofuels
Correct Option: B  [ Molecular analogues ]

Remark: The EFB definition mentions 'molecular analogues for products and services'.

What macromolecules, besides RNA and proteins, must be removed to isolate DNA in a pure form?

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

• Amino acids and sugars
• Polysaccharides and lipids
• Water and salts
• Vitamins and minerals
Correct Option: B  [ Polysaccharides and lipids ]

Remark: To release DNA, the cell must be broken open to release DNA along with RNA, proteins, polysaccharides and also lipids.