Biotechnology: Principles and Processes

Biotechnology: Principles and Processes is one of the highest-yield chapters in the whole Class 12 syllabus — a near-certain source of 3-4 NEET questions every year and a favourite for CBSE 3- and 5-mark questions on recombinant DNA technology. It is built on three pillars: the principles of biotechnology (genetic engineering and bioprocess engineering, and the idea of the origin of replication behind cloning), the tools of recombinant DNA technology (restriction enzymes and palindromes, gel electrophoresis, cloning vectors like pBR322, selectable markers and insertional inactivation, and vectors for plants and animals such as the Ti plasmid), and the processes of recombinant DNA technology (DNA isolation, cutting, PCR amplification with Taq polymerase, insertion into a host, expression of the foreign gene, bioreactors and downstream processing). The chapter rewards precise recall of names and roles — EcoRI and Hind II, DNA ligase, Agrobacterium tumefaciens, Thermus aquaticus, ampicillin and tetracycline resistance, beta-galactosidase — laid over a clear understanding of the workflow from a gene of interest to a purified recombinant protein. By the end you should be able to trace the entire recombinant DNA pipeline, name the tool used at each step, and explain how recombinants are selected from non-recombinants.