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NEET Biotechnology: 5 practice MCQs with answers

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

Biotechnology in Class 12 Biology covers the tools of recombinant DNA technology and their applications in medicine and agriculture. Most NEET questions come from named enzymes, vectors, organisms and products listed in NCERT. The five MCQs below test the recognition sequence of EcoRI, the source of Taq polymerase, Bt cotton, the chains of insulin and the first gene therapy.

What this chapter covers in the NEET syllabus

The NMC unit is Biotechnology and its Applications, taught in NCERT as two Class 12 chapters: Biotechnology: Principles and Processes, and Biotechnology and its Applications. The topics are:

• Principles of biotechnology: genetic engineering and the tools of recombinant DNA technology (restriction enzymes, vectors, host cells).
• The processes: isolation of DNA, cutting, PCR, insertion into a vector, transformation, and the downstream processing of products.
• Applications in health: genetically engineered insulin, gene therapy and molecular diagnosis.
• Applications in agriculture: genetically modified crops, Bt crops, and RNA interference.
• Transgenic animals, and ethical issues including biopiracy and patents.

The NMC PDF is the reference for the exact sub-topic list.

Five practice MCQs on Biotechnology

Question 1

The recognition sequence of the restriction enzyme EcoRI is:

• A. GGATCC
• B. GAATTC
• C. AAGCTT
• D. CCCGGG

Question 2

Taq polymerase, used in PCR, is isolated from the bacterium:

• A. Thermus aquaticus
• B. Escherichia coli
• C. Bacillus thuringiensis
• D. Agrobacterium tumefaciens

Question 3

Bt cotton is genetically modified to be resistant to:

• A. nematodes
• B. fungal wilt
• C. cotton bollworm
• D. aphids

Question 4

The numbers of amino acids in the A chain and the B chain of human insulin are respectively:

• A. 30 and 21
• B. 51 and 21
• C. 21 and 51
• D. 21 and 30

Question 5

The first clinical gene therapy, given in 1990 to a four-year-old girl, was for:

• A. cystic fibrosis
• B. sickle-cell anaemia
• C. adenosine deaminase (ADA) deficiency
• D. haemophilia

Answers and explanations

1. B. EcoRI cuts DNA between G and A in the palindromic sequence GAATTC, leaving sticky ends. GGATCC is the site of BamHI, AAGCTT of HindIII and CCCGGG of SmaI.
2. A. Taq polymerase comes from Thermus aquaticus, a thermophilic bacterium. It stays active through the high temperature needed to denature DNA in each PCR cycle, which a normal polymerase would not survive.
3. C. Bt cotton carries cry genes from Bacillus thuringiensis (cryIAc and cryIIAb) that produce a toxin lethal to the cotton bollworm. The toxin is made as an inactive protoxin that is activated in the alkaline gut of the insect.
4. D. Human insulin has two short polypeptide chains: chain A of 21 amino acids and chain B of 30 amino acids, joined by disulphide bridges. In the body it is made as proinsulin with an extra C peptide that is removed during maturation.
5. C. In 1990 a four-year-old girl with ADA deficiency received the first clinical gene therapy. ADA deficiency results from the deletion of the gene for adenosine deaminase, which is essential for the immune system to function.

How to prepare Biotechnology

• Make a toolkit table. Restriction enzymes (with the examples EcoRI, BamHI, HindIII, SmaI), ligase, DNA polymerase, cloning vectors (pBR322, plasmids, the Ti plasmid, bacteriophages), and host cells (E. coli, Agrobacterium). For each, learn one fact NCERT states.
• Learn the steps in order: isolate DNA, cut with enzymes, separate by gel electrophoresis, amplify by PCR, ligate into the vector, transform the host, select recombinants, and grow in a bioreactor. Draw the PCR cycle (denaturation, annealing and extension).
• Understand selection of recombinants: antibiotic resistance markers and insertional inactivation, for example a foreign gene inserted into the tetracycline resistance gene of pBR322.
• Memorise application names: Humulin (insulin made in E. coli), Bt cotton, RNA interference in tobacco against the root-knot nematode Meloidogyne incognita, and the transgenic cow Rosie.
• Compare the ethical terms: GEAC, biopiracy and patents.

This chapter is name-heavy, so a one-page glossary of enzymes, organisms and products helps most. See the NEET Biology preparation guide for planning, and NCERT for NEET for how to read each line.

Take a full Biotechnology test on PrepMatic

This chapter is name-heavy, so frequent short tests help. If you studied in Tamil medium, you can choose Tamil as your exam language on PrepMatic; topic tests are about 15 questions in 30 minutes with NEET's negative marking. See the practice hub for more chapters.

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