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NEET ZoologyUpdated 19 Oct 2026

Biotechnology: Principles and Processes: NEET PYQs and weightage

Biotechnology: Principles and Processes carries 11.0 of 100 Zoology marks in NEET by past-paper share: 71 of the 648 tagged NEET Zoology PYQs in the ViJEEta bank (NEET 2013–2026). It ranks 1 of 17 Zoology chapters.

Take the 25-question Biotechnology: Principles and Processes testKey facts ↓All NEET Zoology chapters
11.0/100 Weight in Zoology
5 of 5 Exam importance (5/5, by past-paper share)
71 NEET PYQs
493 Practice questions
410 With measured difficulty

How the weight is computed: this chapter's tagged NEET PYQs divided by all tagged NEET Zoology PYQs in the bank (71 of 648), times 100, with repeated questions counted once. The bank does not store the year of each NEET question, so none is printed. Computed from the bank at build time. Updated 19 Oct 2026.

Biotechnology: Principles and Processes: key facts for NEET

16 facts the paper keeps asking, each with how it is asked. Copy it onto one page of your notebook: that page is this chapter's handbook.

  1. Core techniques of modern biotechnology

    Modern biotechnology rests on two core techniques: genetic engineering and bioprocess engineering (keeping a sterile, contamination-free set-up for large-scale growth).

    Asked as: "Maintaining a microbial contamination-free ambience is a feature of which core technique?"

  2. First recombinant DNA

    First recombinant DNA: Stanley Cohen and Herbert Boyer, 1972. An antibiotic-resistance gene was linked to a native plasmid of Salmonella typhimurium, then cloned in E. coli.

    Asked as: "The native plasmid used in the first recombinant DNA belonged to which organism?"

  3. Origin of replication (ori)

    Alien DNA multiplies in a host only when linked to an origin of replication (ori). Ori also controls copy number (some plasmids have – copies per cell, others –).

    Asked as: "Which vector sequence controls the copy number of the linked DNA?"

  4. Discovery of restriction enzymes

    In 1963, two enzymes restricting phage growth in E. coli were isolated: one methylates DNA, the other cuts it. The first sequence-specific restriction endonuclease, Hind II, was isolated 5 years later and recognises bp.

    Asked as: "Name the first restriction endonuclease. How many base pairs does it recognise?"

  5. Naming restriction enzymes

    Naming: first letter = genus, next two letters = species, then the strain letter, then a Roman numeral for order of isolation. EcoRI = Escherichia coli RY 13. Over enzymes are known, from over strains.

    Asked as: "In EcoRI, what do 'R' and 'I' indicate?"

  6. Exonucleases vs endonucleases

    Exonucleases remove nucleotides from DNA ends. Endonucleases cut at specific positions within DNA, in the sugar-phosphate backbone.

    Asked as: Assertion-Reason on exonuclease vs endonuclease.

  7. Palindromic restriction sites

    Restriction sites are palindromes ( / ). The cut is a little away from the centre but between the same two bases on both strands, leaving sticky ends.

    Asked as: "Identify the palindromic sequence" (options given with only one true palindrome).

  8. Sticky ends and DNA ligase

    Sticky ends H-bond with complementary ends, which helps DNA ligase join them. The vector and source DNA must be cut with the same enzyme.

    Asked as: "Why must vector and source DNA be cut by the same restriction enzyme?"

  9. Gel electrophoresis

    Gel electrophoresis: DNA is negatively charged, so it moves to the anode. The matrix is agarose (from seaweeds), and smaller fragments move farther.

    Asked as: "In agarose gel, which fragment travels farthest from the well?"

  10. Visualising bands and elution

    Bands are seen only after ethidium bromide staining plus UV light, as bright orange bands. Cutting bands out and extracting the DNA is called elution.

    Asked as: "Name the stain and radiation used to visualise DNA, and what elution means."

  11. Selectable markers for E. coli

    Selectable markers for E. coli are genes for resistance to ampicillin, chloramphenicol, tetracycline or kanamycin. Normal E. coli resists none of these.

    Asked as: "Which of these is not a selectable marker used for E. coli?"

  12. pBR322 vector

    pBR322 carries ori, rop (codes proteins for plasmid replication), two resistance genes ( and ) and seven restriction sites, among them BamH I, EcoR I and Pst I. Insert at BamH I in : recombinants grow on ampicillin but not on tetracycline.

    Asked as: "Foreign DNA at the BamH I site of pBR322: on which medium will recombinants fail to grow?"

  13. Insertional inactivation (blue-white selection)

    Insert placed in the -galactosidase gene (insertional inactivation) + chromogenic substrate: blue colonies = no insert; colourless colonies = recombinants.

    Asked as: "Recombinant colonies in this method appear ___?"

  14. Vectors for plants and animals

    Ti plasmid of Agrobacterium tumifaciens (transfers T-DNA to dicots) is disarmed into a plant vector. Disarmed retroviruses are used as vectors for animal cells.

    Asked as: "Which plasmid is used as a cloning vector for plants?"

  15. Competent host and DNA transfer methods

    Competent host: treat with a divalent cation (calcium), incubate with rDNA on ice, give a heat shock, then return to ice. Other transfer methods: micro-injection into the animal cell nucleus, and biolistics/gene gun (gold or tungsten particles) for plants.

    Asked as: Match the method with its host (micro-injection, gene gun, heat shock).

  16. DNA isolation, PCR and bioreactors

    Isolating DNA: lysozyme (bacteria), cellulase (plant cells) and chitinase (fungus) break cells open; ribonuclease and protease remove RNA and proteins; chilled ethanol precipitates the DNA, which is then spooled. PCR runs denaturation primer annealing extension, using thermostable DNA polymerase from Thermus aquaticus, and gives about billion copies. Bioreactors (–, usually stirred-tank) are followed by downstream processing (separation and purification).

    Asked as: "Which enzyme breaks open fungal cells?" / "Order the three steps of a PCR cycle."

Trap

In blue-white selection, the blue colonies are the NON-recombinants. Recombinants are colourless, because the insert has inactivated β-galactosidase. In the same way, pBR322 recombinants with an insert at BamH I lose tetracycline resistance.

How does NEET ask Biotechnology: Principles and Processes?

8 real previous-year questions from this chapter, as printed in the paper, each with its worked solution. Answer the first one here with no sign-in.

Q1ZoologyNEET UG PYQTools of Recombinant DNA Technology - Cloning Vectors
Try right here · No sign-in
Plasmid pBR322 has a PstI restriction enzyme site within gene amp that confers ampicillin resistance. If this enzyme is used for inserting a gene for β-galactoside production and the recombinant plasmid is inserted in an E.coli strain
Answer key (C) & worked solution

Correct answer: Option C

pBR322 is a commonly used cloning vector. When the gene for β-galactoside is inserted in the ampicillin resistance gene by using Pst I, the recombinant E.coli will lose ampicillin resistance due to insertional inactivation of the antibiotic resistance gene. The host (recombinant) cell will produce β-galactoside which is not a novel protein nor does it have the dual ability. The transformed cells cannot resist ampicillin as they have lost ampicillin resistance. A recombinant E. coli is produced and the host cell will not undergo lysis due to the insertion of the β-galactoside gene.
Q2ZoologyNEET UG PYQTools of Recombinant DNA Technology - Restriction Enzymes
Identify the wrong statement with regard to restriction enzymes.
AThey are useful in genetic engineering
BSticky ends can be joined by using endonucleases
CEach restriction enzyme functions by inspecting the length of a DNA sequence
DThey cut the strand of DNA at palindromic sites
Answer key (B) & worked solution

Correct answer: Option B

(a) Genetic engineering or recombinant DNA technology can be accomplished only if we have the key tools, i.e., restriction enzymes, polymerase enzymes, ligases, vectors and the host organism. (b) The sticky ends in DNA that result from the action of restriction endonucleases cannot be joined by the restriction enzymes, but by DNA ligases. (c) Restriction enzymes begin their action by first scanning the length of the DNA sequence and then recognising a specific sequence. This specific base sequence is known as the recognition sequence. (d) Each restriction endonuclease recognises a specific palindromic nucleotide sequence in the DNA.
Q3ZoologyNEET UG PYQTools of Recombinant DNA Technology - Restriction Enzymes
The specific palindromic sequence which is recognized by EcoRI is
A5’- CTTAAG – 3’, 3’ GAATTC – 5’
B5’- GGATCC - 3’, 3’- CCTAGG - 5’
C5’- GAATTC - 3’, 3’ -CTTAAG - 5’
D5’- GGAACC - 3’, 3’ - CCTTGG - 5’
Answer key (C) & worked solution

Correct answer: Option C

EcoRI is the restriction enzyme which recognises 6 base pair palindromic sequences and cuts both the strands of DNA at second base in the sequence from 5’ end. It produces sticky ends. GAATTCCTTAAG
Q4ZoologyNEET UG PYQPrinciples of Biotechnology
Choose the correct pair from the following.
ANucleases - Separate the two strands of DNA
BExonucleases - Make cuts at specific positions within DNA
CLigases - Join the two DNA molecules
DPolymerases - Break the DNA into fragments
Answer key (C) & worked solution

Correct answer: Option C

DNA ligase is an enzyme that can connect two DNA molecules together by forming a phosphodiester bond between them. Nucleases cleave the phosphodiester bonds of nucleic acids and can be endo- or exo-nuclease based on the position where it makes the cut. Exonucleases make cuts at the ends of the DNA strand. Polymerases help in the polymerization of a DNA or RNA molecule. DNA polymerases and RNA polymerases are the enzymes that perform this function respectively.
Q5ZoologyNEET UG PYQTools of Recombinant DNA Technology - Restriction Enzymes
Given below are two statements: Statement I: Restriction endonucleases recognise specific sequences to cut DNA known as palindromic nucleotide sequences. Statement II: Restriction endonucleases cut the DNA strand a little away from the centre of the palindromic site. In the light of the above statements, choose the most appropriate answer from the options given below:
ABoth Statement I and Statement II are correct
BBoth Statement I and Statement II are incorrect
CStatement I is correct but Statement II is incorrect
DStatement I is incorrect but Statement II is correct
Answer key (A) & worked solution

Correct answer: Option A

Restriction endonucleases recognise specific sequences to cut DNA known as palindromic nucleotide sequences. However, the restriction enzymes cut the strand of DNA a little away from the centre of the palindrome site, but between the same two bases on the opposite strands.
Q6ZoologyNEET UG PYQTools of Recombinant DNA Technology - Restriction Enzymes
Which one of the following statements is not true regarding gel electrophoresis technique?
AThe process of extraction of separated DNA strands from gel is called elution
BThe separated DNA fragments are stained by using ethidium bromide
CThe presence of chromogenic substrate gives blue coloured DNA bands on the gel
DBright orange coloured bands of DNA can be observed in the gel when exposed to UV light
Answer key (C) & worked solution

Correct answer: Option C

No chromogenic substrates are used during gel electrophoresis. Instead EtBr is used which intercalates between the DNA and it becomes visible under UV light. DNA bands are not visible in the gel unless they are illuminated by UV light.
Q7ZoologyNEET UG PYQTools of Recombinant DNA Technology - Cloning Vectors
The DNA molecule to which the gene of interest is integrated for cloning is called
ATransformer
BVector
CTemplate
DCarrier
Answer key (B) & worked solution

Correct answer: Option B

Vector is an intermediate carrier, a phage, plasmid or virus DNA into which another DNA is inserted for introduction into bacterial or other cells for amplification.
Q8ZoologyNEET UG PYQTools of Recombinant DNA Technology - Restriction Enzymes
In the following palindromic base sequence of DNA, which one can be cut easily by a particular restriction enzyme?
A5’ GATACT 3’ ; 3’ CTATGA 5’
B5’ GAATTC 3’ ; 3’ CTTAAG 5’
C5’ CTCAGT 3’ ; 3’ GAGTCA 5’
D5’ GTATTC 3’ ; 3’ CATAAG 5’
Answer key (B) & worked solution

Correct answer: Option B

The sequence 5’ GAATTC 3’ ; 3’ CTTAAG 5’ is a palindromic sequence and therefore can be cut easily by a restriction endonuclease. The rest of the sequences are not palindromic. 5’ GAATTC 3’ ; 3’ CTTAAG 5’ is, in fact, the recognition sequence of the restriction enzyme EcoRI.

Which topics in Biotechnology: Principles and Processes carry the most questions?

All 9 topics, by tagged PYQs, then practice questions. Counted from the bank. Updated 19 Oct 2026.

TopicPYQsPractice questions
Tools of Recombinant DNA Technology - Restriction Enzymes27101
Tools of Recombinant DNA Technology - Cloning Vectors17140
Amplification of DNA Using PCR949
Processes of Recombinant DNA Technology872
Principles of Biotechnology453
Downstream Processing427
Obtaining the Foreign Gene Product116
Tools of Recombinant DNA Technology - Competent Host116
Miscellaneous Examples019

Why does Biotechnology: Principles and Processes show "–" until you answer 3 questions?

Unknown is not zero. Until you answer at least 3 graded questions in Biotechnology: Principles and Processes, ViJEEta shows – instead of a zero or a 50% default. Book exercises can raise chapter mastery up to 0.60, adaptive practice up to 0.75, and only a timed chapter test or mock can certify 0.80 and above.

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What happens when you test Biotechnology: Principles and Processes?

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Chapters either side of Biotechnology: Principles and Processes by weight

Animal Kingdom Weight 8.5/100Biomolecules Weight 8.3/100