Section 16 — NEET-Pattern Practice Questions (Biotechnology: Principles and Processes)
Biotechnology: Principles and Processes is a high-yield, high-reliability NEET chapter — you can expect 2 to 4 questions from it almost every year, and they are usually gettable once your facts are tight. The questions sweep across the whole chapter: the two principles (genetic and bioprocess engineering), the tools (restriction enzymes, gel electrophoresis, cloning vectors, selectable markers), and the processes (isolation of DNA, cutting, PCR, insertion into a host, expression, bioreactors and downstream processing).
This section is a focused 28-question NEET-pattern practice quiz covering the entire chapter — mostly precise recall (which enzyme does what, which organism a tool comes from, what temperature or copy number applies) with a few concept traps (exonuclease vs endonuclease, sticky ends, insertional inactivation).
Important note: These are NEET-pattern practice questions built on the recurring core concepts of this chapter. Do not treat them as exact authenticated year-tagged questions unless each one is separately matched against an official paper and year.
How to use: Treat this like a timed mock — give yourself about 25 minutes for all 28 questions. Attempt first, then read each explanation carefully. Use the Mini Recap below to spot the recurring question patterns before you begin.
Mini Recap — Recurring NEET Hooks for This Chapter
Most questions on this chapter fall into a handful of predictable patterns. Fix these before you start.
1. The enzymes. Restriction endonucleases cut DNA at specific internal sites (the molecular scissors); exonucleases remove nucleotides from the ends. DNA ligase joins cut ends. DNA polymerase builds new strands; the thermostable Taq polymerase from Thermus aquaticus is the one used in PCR. Enzymes that break cells open — lysozyme (bacteria), cellulase (plant cells), chitinase (fungus); ribonuclease removes RNA and protease removes protein during DNA isolation.
2. The naming convention. In EcoRI, the first letter is the genus (Escherichia), the next two the species (coli), the next letter the strain (RY13), and the Roman numeral the order of isolation. Hind II was the first restriction endonuclease characterised, recognising a six-base-pair sequence.
3. Palindromes and sticky ends. A restriction enzyme recognises a palindromic sequence that reads the same on both strands. It cuts away from the centre, leaving overhanging single-stranded sticky ends that form hydrogen bonds with complementary counterparts — which is why the same enzyme must cut both the vector and the source DNA.
4. Vectors and markers. A cloning vector needs an origin of replication (also controls copy number), a selectable marker (antibiotic-resistance genes such as ampicillin, tetracycline, kanamycin, chloramphenicol) and cloning sites. pBR322 is the classic vector; insertion at the BamHI site of the tetracycline gene causes insertional inactivation. The β-galactosidase / blue-white system is the colour-based alternative. Ti plasmid of Agrobacterium tumefaciens delivers genes into plants; disarmed retroviruses deliver into animal cells.
5. PCR and the processes. PCR uses two primers and Taq polymerase across three repeated steps — denaturation, annealing, extension — amplifying a segment about a billion times. Getting DNA into a competent host uses divalent calcium ions and a 42°C heat shock; other routes are micro-injection and the gene gun (biolistics). Scale-up uses bioreactors (100–1000 litres), followed by downstream processing (separation, purification, formulation, quality control).