ISC Class 12 Biotechnology Syllabus 2026-27

ISC Class 12 Biotechnology is a highly specialised and career-oriented subject offered under the CISCE board. It bridges molecular biology, genetic engineering, cell culture, and bioinformatics into a single comprehensive curriculum, giving students a strong foundation for careers in biotech research, medicine, agriculture, pharmaceuticals, and data sciences.

The subject is equally relevant for students preparing for NEET, CUET, and undergraduate admissions in Biotechnology, Bioinformatics, Biochemistry, Microbiology, and related fields. Practical skills are also assessed rigorously through 15 prescribed experiments and project work.

Exam Structure

Unit-Wise Marks Weightage (Theory - 70 Marks)

Genetic Engineering carries 23 marks - the highest of all four units. Prioritise it most in your preparation.

Unit 1: Molecular Biology (15 Marks)

This unit covers the biochemical basis of heredity and gene expression, from DNA structure to protein synthesis and gene regulation in prokaryotes.

(i) Nucleic Acids and Their Estimation

•        Units of nucleic acids: nucleotides; difference between nucleosides and nucleotides

•        DNA structure: Watson-Crick double helix model, Chargaff's Equivalence Rule (A=T, G=C)

•        DNA as genetic material: Hershey and Chase experiment

•        RNA types and roles: mRNA (monocistronic and polycistronic), tRNA, rRNA; tRNA in Clover leaf model (2D) and inverted L-shaped model (3D)

•        DNA replication: Meselson-Stahl experiment and Taylor et al. experiment; leading and lagging strands

•        Enzymes in replication: Topoisomerase, Helicase, SSBPs, Primase, DNA Polymerase, DNA Ligase

•        Proofreading and repair by DNA Polymerase I and II

•        Estimation of nucleic acids: UV-visible spectrophotometry and colorimetry

(ii) Protein Synthesis: Central Dogma, Transcription and Translation

•        Transcriptional unit: Promoter region, Structural region, Terminator region; split genes (exons and introns); hnRNA

•        Transcription process: Initiation, Elongation, Termination with enzymes involved

•        Post-transcriptional modifications: polyadenylation, capping, RNA splicing; role of snRNA in splicing

•        Genetic code: properties; start and stop codons

•        Translation: Initiation, Elongation, Termination; post-translational modifications: glycosylation, protein folding, proteolytic degradation, intein splicing

•        Reverse transcription: process and significance as an exception to the Central Dogma

(iii) Gene Regulation in Prokaryotes

•        Types of operons: Inducible (lac operon) and Repressible (trp operon)

•        Lac operon: structure, working, and induction mechanism by lactose (allolactose)

•        Trp operon: structure, working, and repression mechanism when tryptophan is present

Unit 2: Genetic Engineering (23 Marks)

This is the highest-weightage unit carrying 23 marks. It covers the complete toolkit of recombinant DNA technology, modern innovations, and analytical techniques.

(i) Tools and Techniques of Gene Cloning

•        Restriction endonucleases: Type I, II and III - differences and roles; examples of specific enzymes (EcoRI)

•        Other key enzymes: DNA ligase, alkaline phosphatase, Taq polymerase, RNase, S1 nuclease, polynucleotide kinase, exonuclease, DNA polymerases I, II and III

•        DNA isolation and purification: from bacterial, plant and animal cells; purification using CTAB method

•        Vectors: Plasmids (pBR322, pUC), Phages (M13 and lambda), Phagemids, Cosmids, YACs, BACs with specific carrying capacities

•        Transformation methods (vector-less): Electroporation, liposome-mediated, microinjection, biolistics

•        Transformation (vector-mediated): Agrobacterium-mediated method

•        Identification of recombinants: Green Fluorescent Protein (GFP) direct selection, insertional inactivation (antibiotic resistance, blue-white selection)

•        Genomic DNA and cDNA libraries

(ii) Innovations in Biotechnology

•        GM Crops: Flavr Savr tomatoes, Bt-crops, Golden rice

•        Gene editing and therapy: CRISPR-Cas9 technology for sickle cell anaemia and cancer

•        Recombinant products: Humulin (insulin), recombinant interferons

•        Vaccines and therapies: Recombinant Hepatitis B vaccine, mRNA-based Covid-19 vaccine, stem cell therapy

•        Transgenic animals: Dolly sheep, Rosie cow, ATryn goat; development of artificial meat without slaughter

•        Bioremediation: oil-eating bacteria (Super Bug); Mycoremediation: Pleurotus ostreatus (diesel/motor oils); Phycoremediation: Chlamydomonas (heavy metals, crude oils)

•        Industrial enzymes: Rennet, Subtilisin, Amylase, Papain with sources and applications

(iii) Gene Analysis Techniques

•        DNA probes: definition and use in gene detection

•        Gel electrophoresis: process and applications

•        Blotting: Southern (DNA), Northern (RNA), Western (protein) blotting - what each detects

•        DNA sequencing: Sanger's chain termination method using ddNTPs, automated DNA sequencing

•        Site-directed mutagenesis: principle with example of human insulin

•        PCR: process and applications; RT-PCR; DNA fingerprinting

Know Southern (DNA), Northern (RNA) and Western (protein) blotting as a set. This distinction is frequently tested.

Unit 3: Cell Culture Technology (20 Marks)

This unit covers microbial, plant tissue, and animal cell culture technologies and their wide-ranging industrial and medical applications.

(i) Microbial Culture

•        Fermentation types: batch, fed-batch, and continuous cultures with principles, products, and graphs for each

•        Turbidostat vs Chemostat: both are forms of open continuous culture; turbidostat varies dilution rate to maintain constant turbidity; chemostat fixes dilution rate with a limiting nutrient

•        Bioreactor design: components and downstream processing with reference to antibiotic production

•        Single Cell Protein (SCP): large-scale mycoprotein production using yeast by fermentation

(ii) Plant Tissue Culture

•        Totipotency: definition; cellular differentiation, de-differentiation, re-differentiation with respect to callus formation

•        Haploid production: androgenesis (from anther/pollen) and gynogenesis (from egg)

•        Triploid production: endosperm culture

•        In-vitro pollination and embryo rescue

•        Embryo culture; somatic hybridisation: Pomato (potato + tomato) as the specific example

•        Micropropagation; virus-resistant plants by RNAi

•        Somatic embryogenesis and synthetic seeds; PHB (bioplastics) production

(iii) Animal Cell Culture

•        Primary culture, secondary culture/sub-culture; suspension (suspension cell line) and monolayer (adherent cell line)

•        Cell lines: finite and continuous types and their differences

•        Scale up: Roller bottle culture technique

•        Hybridoma technology: fusion of B-cells with myeloma cells to produce monoclonal antibodies

•        CAR-T therapy: genetically engineered T-cells to cure cancer (Chimeric Antigen Receptor T-cell therapy)

Unit 4: Bioinformatics (12 Marks)

Bioinformatics applies computational tools and databases to analyse biological data, particularly DNA, RNA, and protein sequences.

(i) Introduction to Bioinformatics

•        Definition and need of bioinformatics

•        Global databases: EMBL, NCBI, DDBJ, SWISSPROT, GenBank - know what each stores

•        Data retrieval tools: ENTREZ and Taxonomy Browser

(ii) Genomics

•        Types of genomics: Structural, Functional, and Metagenomics with definitions

•        Sequence types: cDNA, ESTs, STSs

•        Sequence alignment tools: BLAST and FASTA; global, local, pairwise and multiple sequence alignments

•        Genome projects: Human Genome Project and Rice Genome Project - objectives, achievements, countries involved, key contributors

•        DNA Microarray: definition and application

•        SNPs: concept and significance in genomics

(iii) Proteomics

•        Types of proteomics: Structural, Functional, and Expression

•        Protein databases: PDB, PIR, SWISSPROT

•        Protein engineering: definition, principle and application

•        AlphaFold2: AI system for protein structure prediction; application in Covid-19 vaccine and cancer therapy

Paper II: Practical Work (15 Marks)

Candidates must complete 15 prescribed experiments. The practical paper is 3 hours and tests hands-on laboratory skills.

List of Prescribed Experiments

•        Experiment 1: Paper chromatography - separation of photosynthetic pigments (carotenes, chlorophyll A, chlorophyll B)

•        Experiment 2: Preparation of buffers - phosphate, acetate and borate buffers (pH range 4 to 9.2)

•        Experiment 3: Preparation of culture media - LB medium (bacterial) and MS medium (plant tissue culture) as slants and suspensions

•        Experiment 4: Sterilisation of culture medium - dry (heat/radiation), wet (steam/autoclave), chemical (70% alcohol, sodium hypochlorite, carbolic acid)

•        Experiment 5: Inoculation and incubation of Lactobacillus on culture medium using inoculation loop/needle

•        Experiment 6: Identification of bacteria by Gram staining - crystal violet → iodine → ethanol → safranin

•        Experiment 7: Action of salivary amylase on starch at variable temperature and variable substrate concentration (plotting Km value by graph)

•        Experiment 8: Isolation of DNA from plants (banana, pea seeds, wheat grains)

•        Experiment 9: DNA estimation by colorimeter using DPA method

•        Experiment 10: Protein estimation by Bradford Test (Coomassie Brilliant Blue G-250 dye; BSA as standard)

•        Experiment 11: Cell viability test by Trypan Blue Dye (dead cells = blue, live cells = clear)

•        Experiment 12: Isolation of milk protein (casein) - precipitates at isoelectric point pH 4.6 using 0.4 N HCl

•        Experiment 13: Cell counting by Haemocytometer using diluted blood

•        Experiment 14: Saponification process

•        Experiment 15: Separation of amino acids by paper chromatography

Gram staining steps in order: crystal violet → water rinse → iodine → 90% ethanol → safranin. Gram positive = blue/purple; Gram negative = red.

Project Work and Practical File (15 Marks)

Project Work (10 marks) and Practical File (5 marks) are both assessed by a Visiting Examiner appointed locally and approved by CISCE.

Project Work (10 Marks)

Students creatively execute one project on an aspect of Biotechnology. The report should be simple, neat and elegant. Evaluation format: Introduction, Content, Presentation (graphs/tables/diagrams), Conclusion/Summary, Bibliography.

Suggested project topics: Effluent analysis, Brewing industry role of biotechnology, Drug designing via AI and proteomics, Vaccine/drug development, Disease diagnosis (ELISA/RIA), DNA Fingerprinting, Microbial identification techniques, Tissue Culture, Stem Cell Technology, Nanotechnology, Bioinformatics, Gene and animal cloning, Forensic Biotechnology, Ethical/Legal/Social Issues (ELSI) of GMOs, Biopiracy case studies.

Practical File (5 Marks)

All 15 experiments must be recorded date-wise throughout the year. Each entry must be checked, signed, and dated by the teacher.

Key Abbreviations

Preparation Strategy for ISC Biotechnology 2026-27

Unit 1 - Molecular Biology

•        Know the difference between nucleoside and nucleotide precisely - this is explicitly listed

•        tRNA: know both Clover leaf (2D) and inverted L-shaped model (3D) - both are listed

•        Enzymes in replication: know the role and order of all six enzymes from topoisomerase to ligase

•        Know both operons: lac (inducible) and trp (repressible) - structure and working

•        Post-translational modifications: all four (glycosylation, protein folding, proteolytic degradation, intein splicing) must be known

Unit 2 - Genetic Engineering

•        Highest-weightage unit at 23 marks - prepare it most thoroughly

•        Restriction enzymes: know all three types (I, II, III) and their differences

•        Vectors: know carrying capacities for all listed vectors - plasmids, phages, phagemids, cosmids, YACs, BACs

•        Blotting: Southern = DNA, Northern = RNA, Western = protein

•        Bioremediation: all three types with specific organisms and their specific substrates

•        CRISPR-Cas9: know the application for sickle cell anaemia and cancer specifically

Unit 3 - Cell Culture

•        Fermentation: know graphs and principles for batch, fed-batch, and continuous cultures

•        Turbidostat vs Chemostat: both are open continuous cultures - know the key difference

•        Totipotency pathway: differentiation → de-differentiation → callus → re-differentiation

•        Pomato: somatic hybridisation of potato and tomato protoplasts

•        CAR-T therapy: genetically engineered T-cells targeting cancer cells

Unit 4 - Bioinformatics

•        Know all five databases: EMBL, NCBI, DDBJ, SWISSPROT, GenBank and what each stores

•        BLAST vs FASTA: both are sequence alignment tools - know what each does

•        Both genome projects: Human Genome Project and Rice Genome Project - objectives, achievements, countries, contributors

•        AlphaFold2: AI for protein structure prediction; application in Covid-19 and cancer

Frequently Asked Questions

Q1. Which unit carries the most marks?

Genetic Engineering carries 23 marks - the highest of all four units.

Q2. What is the difference between Southern, Northern and Western blotting?

Southern blotting detects specific DNA sequences. Northern blotting detects specific RNA sequences. Western blotting detects specific proteins.

Q3. What are the two types of operons and their examples?

Inducible: lac operon (induced by lactose). Repressible: trp operon (repressed when tryptophan is present). Both are required with structure and working.

Q4. What CRISPR applications are listed in the syllabus?

Gene therapy of sickle cell anaemia and cancer using CRISPR-Cas9 to insert knockout genes.

Q5. What is the difference between turbidostat and chemostat?

Both are open continuous cultures. In a turbidostat, dilution rate varies to maintain constant cell density. In a chemostat, dilution rate is fixed and a limiting nutrient controls growth rate.

Q6. What is Pomato?

Pomato is the result of somatic hybridisation between potato and tomato protoplasts. It is the specific example given in the syllabus for somatic hybridisation.

Q7. What is CAR-T therapy?

Chimeric Antigen Receptor T-cell therapy. T-cells are genetically engineered to express a receptor that targets and kills cancer cells.

Q8. What is AlphaFold2?

An AI system that predicts protein 3D structures. Listed in the syllabus for its use in developing vaccines against Covid-19 and in cancer therapy.

Source Reference

Based on the official CISCE ISC Biotechnology Syllabus issued by RDCD, CISCE. Verify at cisce.org before the examination.