Biology · Biotechnology: Principles and Processes · NEET
NCERT lists exactly two. (1) Genetic engineering: techniques to alter the chemistry of genetic material (DNA and RNA), introduce this into a host organism, and thus change the phenotype (traits) of the host. (2) Bioprocess engineering: keeping a sterile, contamination-free setup in chemical engineering so that only the desired microbe or eukaryotic cell grows in large quantity to make products like antibiotics, vaccines and enzymes. Remember both — NEET often asks 'which is NOT a core technique'.
NCERT says three basic steps are needed to genetically modify an organism: (i) identification of the DNA with the desirable gene, (ii) introduction of the identified DNA into the host, and (iii) maintenance of the introduced DNA in the host and transfer of that DNA to its progeny (offspring). If step (iii) fails, the new gene is lost when the cell divides, so simply pushing DNA in is not enough — it must be able to replicate and be inherited.
Sexual reproduction shuffles genes but you cannot control which genes combine, and it only works between closely related organisms. Genetic engineering (recombinant DNA technology, gene cloning, gene transfer) lets us take one specific, isolated gene and put it into an organism that would never receive it naturally — for example a human gene into a bacterium. This gives precise, targeted control that traditional hybridisation cannot.
NCERT uses the mosquito analogy: just as a mosquito is a vector that carries the malarial parasite into the human body, a plasmid acts as a vector that carries an alien piece of DNA into a host cell. To build the recombinant DNA, restriction enzymes ('molecular scissors') cut the DNA, and DNA ligase joins the cut foreign DNA to the cut plasmid, making a new combination of circular autonomously replicating DNA.
No. Genetic engineering makes the modified organism. Bioprocess engineering comes after: it grows that organism at large scale. The key idea is a sterile (contamination-free) environment inside a bioreactor so only the desired cell grows, plus control of temperature, pH, oxygen and nutrients. This is how the recombinant product (like insulin or an antibiotic) is manufactured in useful amounts.
A foreign DNA and plasmid cut by the same restriction endonuclease can be joined to form a recombinant plasmid using
Which of the following can act as molecular scissors?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Genetic engineering (alter DNA/RNA and put it into a host to change its traits) and bioprocess engineering (grow the desired organism in a sterile setup to make products at large scale).
They are very closely linked. Recombinant DNA technology, gene cloning and gene transfer are the tools of genetic engineering — the set of techniques used to alter and transfer genetic material into a host.
It explains how a modified organism is turned into a real product. The exam-key idea is the sterile, contamination-free environment in a bioreactor so only the wanted microbe or cell grows in large quantity.
It means the introduced DNA must be able to replicate and pass to daughter cells (progeny). Vectors provide an origin of replication so the foreign gene is kept and inherited, not lost during cell division.
