Biotechnology—Principles and Processes — BIOLOGY STD 12 Science — Question

 (a) PCR: The polymerase chain reaction (PCR) was originally developed in 1983 by the American biochemist Kary Mullis. He was awarded the Nobel Prize in Chemistry in 1993 for his pioneering work. PCR is used in milecular biology to make many copies of (amplify) small sections of DNA or a gene. Using PCR it is possible to generate thousands to millions of copies of a particular section of DNA from a very small amount of DNA. PCR is common tool used in medical and biological research labs. It is used in the early stages of processing DNA for sequencing, for detecting the presence or absence of a gene to help identify pathogens during infection, and when generating forensic DNA profiles from tiny samples of DNA.
PCR involves a process of heating and cooling called thermal cycling which is carried out by machine.
(b) Restriction enzyme and DNA: Restriction enzyme, also called restriction endonuclease, a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organism. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms. Restriction enzymes can be isolated from bacterial cells and used in the laboratory to manipulate fragments of DNA, such as those that contain genes; for this reason they are indispensible tools recombinant DNA technology (genetic engineering).
(c) Chitinase: Chitinases are hydrolytic enzymes that breakdown glycosidic bonds in chitin. As chitin is a component of the cell walls of fungi and exoskeletal elements of some animals (including molluscs and arthropods), chitinases are generally found in organisms that either need to reshape their own chitin or dissolve and digest the chitin of fungi or animals.
Chitinase activity can also be detected in human blood and possible cartilage. As in plant chitinases this many be related to pathogen resistance.