Chapter 11: Biotechnology: Principles and Processes

Ans: Antibiotic resistance genes in a vector usually help in the selection of transformed cells i.e, they act as a selectable marker. Selectable markers help in identifying the transformed cells. Generally, antibiotics such as Chloramphenicol, tetracycline, ampicillin are considered useful selectable markers.

Hence, option (b) is the correct choice.

Ans: Heat shock method in bacterial transformation is to facilitate uptake of DNA through transient pores in the bacterial cell wall.

In this method presence of bivalent cation like Ca⁺² creates transient pores in the cell wall allowing the uptake of foreign DNA from the surrounding.

Hence, option (c) is the correct choice.

Ans: DNA ligase is an enzyme that facilitates the joining of sticky ends of two DNA strands by the formation of phosphodiester bonds.

Hence, option (a) is the correct choice.

Ans: Entamoeba coli is a protozoa. Therefore, it's not a source of restriction endonuclease.

Hence, option (c) is the correct choice.

Ans: Extension of primer end on the template DNA catalysed by Taq DNA polymerase in a PCR reaction.

Hence, option (c) is the correct choice.

Ans: 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 because the human gene may have an intron that bacteria cannot process. Any nucleotide sequence in a gene is removed by splicing during the maturation of RNA which is called an intron. Hence, option (a) is the correct choice.

Ans: To grow something it requires a growth media and for producing recombinant protein in large amounts continuous culture system is a must.

Hence, option (c) is the correct choice.

Ans: Karry Mullis invented a technique called Polymerase Chain Reaction (PCR) by which large amounts of DNA can be formed from small amounts.

Hence, option (c) is the correct choice.

Ans: Restriction enzymes are isolated from bacteria, not from viruses.

Hence, option (c) is the correct choice.