ISC Class 12 Biology Important Topics 2027
Last updated:
Every topic ranked by how often and how recently it was asked in 4 board + 5 official sample papers (2023–2027). Teal tags = board papers, orange tags = official sample papers.
Top 10 most important topics
| # | Topic | Chapter | Asked in | Importance |
|---|---|---|---|---|
| 1 | restriction enzyme nomenclature | Biotechnology: Principles and Processes | Board 2026Sample 2026Sample 2027 | ★★★★★ |
| 2 | age pyramids - expanding, stable, declining | Organisms and Populations | Board 2023Sample 2026Sample 2027 | ★★★★★ |
| 3 | productivity - NPP = GPP - respiration | Ecosystem | Board 2025Sample 2024Sample 2027 | ★★★★☆ |
| 4 | structure of anatropous ovule | Sexual Reproduction in Flowering Plants | Board 2023Sample 2024Sample 2027 | ★★★★☆ |
| 5 | palindromic recognition sequence; reverse transcription | Biotechnology: Principles and Processes | Sample 2025Sample 2027 | ★★★★☆ |
| 6 | insertional inactivation - pBR322 selectable markers | Biotechnology: Principles and Processes | Sample 2025Sample 2027 | ★★★★☆ |
| 7 | lactational amenorrhoea - natural contraception | Reproductive Health | Board 2025Sample 2023Sample 2024 | ★★★☆☆ |
| 8 | embryonic development - blastocyst, trophoblast, inner cell mass | Human Reproduction | Sample 2024Sample 2027 | ★★★☆☆ |
| 9 | interferons - antiviral proteins | Human Health and Diseases | Sample 2024Sample 2027 | ★★★☆☆ |
| 10 | population growth models - logistic / sigmoid curve | Organisms and Populations | Board 2026Sample 2027 | ★★★☆☆ |
Chapter-wise important topics
Sexual Reproduction in Flowering Plants · Reproduction
| structure of anatropous ovule asked 3× | Board 2023Sample 2024Sample 2027 | ★★★★☆ |
| double fertilisation - endosperm ploidy asked 2× | Board 2025Sample 2025 | ★★☆☆☆ |
| female gametophyte - monosporic embryo sac development asked 1× | Sample 2027 | ★★☆☆☆ |
| pollen viability; polyembryony and parthenocarpy asked 1× | Sample 2027 | ★★☆☆☆ |
| ploidy - endosperm and megaspore mother cell asked 1× | Sample 2026 | ★★☆☆☆ |
| pollination types - dioecy rules out selfing asked 1× | Sample 2026 | ★★☆☆☆ |
| microsporogenesis - pollen grain (male gametophyte) number asked 1× | Sample 2026 | ★★☆☆☆ |
| pollination types (autogamy, geitonogamy, xenogamy); Salvia pollination mechanism asked 1× | Sample 2026 | ★★☆☆☆ |
| apomixis - retention of parental characters asked 1× | Sample 2025 | ★☆☆☆☆ |
| female gametophyte - ploidy of antipodal cells asked 1× | Sample 2025 | ★☆☆☆☆ |
| self-pollination - inbreeding and elimination of harmful alleles asked 1× | Sample 2025 | ★☆☆☆☆ |
| embryo development - suspensor (haustorium and hypophysis) asked 1× | Sample 2025 | ★☆☆☆☆ |
| albuminous and non-albuminous seeds asked 1× | Sample 2025 | ★☆☆☆☆ |
| pollination - entomophily and pollen adaptations asked 1× | Sample 2025 | ★☆☆☆☆ |
| pollen grain - generative cell asked 1× | Sample 2024 | ★☆☆☆☆ |
| pollination - hydrophily; self vs cross pollination asked 1× | Sample 2024 | ★☆☆☆☆ |
| double fertilisation - endosperm ploidy (3n) asked 1× | Board 2026 | ★☆☆☆☆ |
| microsporogenesis - pollen grain number asked 1× | Board 2026 | ★☆☆☆☆ |
| pollination types - cleistogamy as autogamy asked 1× | Board 2026 | ★☆☆☆☆ |
| embryo development - apical and basal cell fate asked 1× | Board 2026 | ★☆☆☆☆ |
| artificial hybridisation (emasculation, bagging); pollen-pistil interaction asked 1× | Board 2026 | ★☆☆☆☆ |
| structure of pollen grain / microspore asked 1× | Sample 2023 | ★☆☆☆☆ |
| embryo sac structure; double fertilisation asked 1× | Sample 2023 | ★☆☆☆☆ |
| endosperm - free-nuclear liquid endosperm of coconut asked 1× | Board 2025 | ★☆☆☆☆ |
| female gametophyte - polar nuclei of central cell asked 1× | Board 2025 | ★☆☆☆☆ |
| outbreeding devices; apomixis vs polyembryony asked 1× | Board 2025 | ★☆☆☆☆ |
| microsporangium - archesporial cell asked 1× | Board 2024 | ★☆☆☆☆ |
| endosperm types - nuclear, cellular, helobial asked 1× | Board 2024 | ★☆☆☆☆ |
| true and false fruit; fruit structure asked 1× | Board 2024 | ★☆☆☆☆ |
| structure of anther / microsporangium asked 1× | Board 2024 | ★☆☆☆☆ |
| pollination types - xenogamy, geitonogamy asked 1× | Board 2024 | ★☆☆☆☆ |
| double fertilisation; parthenocarpy and apomixis asked 1× | Board 2024 | ★☆☆☆☆ |
| seed - perisperm asked 1× | Board 2023 | ★☆☆☆☆ |
| triple fusion asked 1× | Board 2023 | ★☆☆☆☆ |
| outbreeding devices to prevent self-pollination asked 1× | Board 2023 | ★☆☆☆☆ |
Human Reproduction · Reproduction
| embryonic development - blastocyst, trophoblast, inner cell mass asked 2× | Sample 2024Sample 2027 | ★★★☆☆ |
| microscopic anatomy of ovary asked 2× | Board 2024Sample 2027 | ★★★☆☆ |
| Leydig and Sertoli cells; corpus luteum vs placenta; zona pellucida; myometrium asked 1× | Sample 2027 | ★★☆☆☆ |
| placenta / chorionic villi asked 1× | Sample 2026 | ★★☆☆☆ |
| structure of sperm - correct labelling asked 1× | Sample 2026 | ★★☆☆☆ |
| menstrual cycle - hormonal control and ovulation timing asked 1× | Sample 2026 | ★★☆☆☆ |
| sperm structure - mitochondria in middle piece asked 1× | Sample 2025 | ★☆☆☆☆ |
| embryonic development - morula asked 1× | Sample 2025 | ★☆☆☆☆ |
| oogenesis - ploidy of oocytes asked 1× | Sample 2024 | ★☆☆☆☆ |
| structure of ovum - zona pellucida and block to polyspermy asked 1× | Sample 2024 | ★☆☆☆☆ |
| menstrual cycle - hormonal control; menstrual vs estrus cycle asked 1× | Sample 2024 | ★☆☆☆☆ |
| structure of mammalian testis asked 1× | Sample 2024 | ★☆☆☆☆ |
| spermatogenesis - spermiogenesis and sperm structure asked 1× | Board 2026 | ★☆☆☆☆ |
| oogenesis; comparison with spermatogenesis asked 1× | Board 2026 | ★☆☆☆☆ |
| gametogenesis - number of gametes from primary cells asked 1× | Sample 2023 | ★☆☆☆☆ |
| oogenesis / menstrual cycle - oocytes ovulated asked 1× | Board 2025 | ★☆☆☆☆ |
| capacitation of sperm during fertilisation asked 1× | Board 2025 | ★☆☆☆☆ |
| parturition - hormonal control asked 1× | Board 2025 | ★☆☆☆☆ |
| microscopic anatomy of testis asked 1× | Board 2025 | ★☆☆☆☆ |
| embryonic development - timeline of foetal development asked 1× | Board 2024 | ★☆☆☆☆ |
| menstrual cycle - luteal / secretory phase asked 1× | Board 2024 | ★☆☆☆☆ |
| spermatogenesis - stages and spermiogenesis asked 1× | Board 2024 | ★☆☆☆☆ |
| Leydig cells - testosterone secretion asked 1× | Board 2023 | ★☆☆☆☆ |
| menstrual cycle - phases and hormonal control asked 1× | Board 2023 | ★☆☆☆☆ |
Reproductive Health · Reproduction
| lactational amenorrhoea - natural contraception asked 3× | Board 2025Sample 2023Sample 2024 | ★★★☆☆ |
| assisted reproductive technology - ICSI asked 2× | Sample 2023Sample 2027 | ★★★☆☆ |
| birth control - copper releasing IUDs asked 2× | Board 2024Sample 2027 | ★★★☆☆ |
| MTP - regulation to prevent female foeticide asked 1× | Sample 2027 | ★★☆☆☆ |
| assisted reproductive technology - ZIFT stage asked 1× | Sample 2026 | ★★☆☆☆ |
| birth control - condom and vasectomy asked 1× | Sample 2026 | ★★☆☆☆ |
| STD - gonorrhoea (Neisseria gonorrhoeae) asked 1× | Sample 2025 | ★☆☆☆☆ |
| birth control - oral contraceptive (Saheli) asked 1× | Sample 2025 | ★☆☆☆☆ |
| assisted reproductive technologies; STDs asked 1× | Sample 2025 | ★☆☆☆☆ |
| birth control - surgical / effective methods asked 1× | Sample 2024 | ★☆☆☆☆ |
| infertility and assisted reproductive technologies asked 1× | Sample 2024 | ★☆☆☆☆ |
| assisted reproductive technology - intra-uterine insemination asked 1× | Board 2026 | ★☆☆☆☆ |
| STD - genital warts (HPV) asked 1× | Sample 2023 | ★☆☆☆☆ |
| birth control - intra-uterine contraceptive device asked 1× | Sample 2023 | ★☆☆☆☆ |
| RCH programme benefits asked 1× | Sample 2023 | ★☆☆☆☆ |
| infertility - male causes asked 1× | Sample 2023 | ★☆☆☆☆ |
| MTP; amniocentesis; IUDs (Cu7, LNG-20) asked 1× | Sample 2023 | ★☆☆☆☆ |
| amniocentesis - prenatal genetic testing asked 1× | Board 2025 | ★☆☆☆☆ |
| sexually transmitted diseases; barrier contraception asked 1× | Board 2025 | ★☆☆☆☆ |
| assisted reproductive technology - ZIFT asked 1× | Board 2023 | ★☆☆☆☆ |
| PID - pelvic inflammatory disease / STD asked 1× | Board 2023 | ★☆☆☆☆ |
| population explosion and birth control methods asked 1× | Board 2023 | ★☆☆☆☆ |
Principles of Inheritance and Variation · Genetics and Evolution
| mutation - frame-shift (deletion) asked 1× | Sample 2027 | ★★☆☆☆ |
| pedigree analysis - autosomal dominant (Marfan syndrome); ideal genetic material asked 1× | Sample 2027 | ★★☆☆☆ |
| sex-linked inheritance - colour blindness probability asked 2× | Board 2023Sample 2023 | ★★☆☆☆ |
| dihybrid cross - phenotypic proportion asked 1× | Sample 2026 | ★★☆☆☆ |
| pleiotropy - sickle cell anaemia asked 1× | Sample 2026 | ★★☆☆☆ |
| ABO blood group - multiple alleles and pedigree asked 1× | Sample 2026 | ★★☆☆☆ |
| dihybrid / monohybrid cross - F2 phenotype numbers asked 1× | Sample 2025 | ★☆☆☆☆ |
| chromosome number - meiosis and ploidy asked 1× | Sample 2025 | ★☆☆☆☆ |
| pedigree analysis - phenylketonuria (Mendelian disorder) asked 1× | Sample 2025 | ★☆☆☆☆ |
| sex determination in humans asked 1× | Sample 2024 | ★☆☆☆☆ |
| chromosomal disorders - aneuploidy (Klinefelter's) asked 1× | Sample 2024 | ★☆☆☆☆ |
| incomplete dominance - Andalusian fowl asked 1× | Sample 2024 | ★☆☆☆☆ |
| phenylketonuria - phenylalanine hydroxylase deficiency asked 1× | Board 2026 | ★☆☆☆☆ |
| chromosomal disorders - Klinefelter's syndrome asked 1× | Board 2026 | ★☆☆☆☆ |
| monohybrid cross - phenotypic ratio asked 1× | Board 2026 | ★☆☆☆☆ |
| sex determination in honey bees (haplodiploidy) asked 1× | Board 2026 | ★☆☆☆☆ |
| pedigree analysis - dominance and linkage asked 1× | Sample 2023 | ★☆☆☆☆ |
| linkage; sex-linked test cross in Drosophila asked 1× | Sample 2023 | ★☆☆☆☆ |
| sex-linked inheritance - haemophilia pedigree asked 1× | Board 2025 | ★☆☆☆☆ |
| sex-linked inheritance - haemophilia probability asked 1× | Board 2024 | ★☆☆☆☆ |
| pedigree analysis - thalassaemia genotype asked 1× | Board 2024 | ★☆☆☆☆ |
| sex determination - discovery of X chromosome (Henking) asked 1× | Board 2024 | ★☆☆☆☆ |
| sickle cell anaemia - point mutation and inheritance asked 1× | Board 2024 | ★☆☆☆☆ |
| incomplete dominance - F1/F2 ratios asked 1× | Board 2024 | ★☆☆☆☆ |
| pedigree analysis - sickle cell anaemia asked 1× | Board 2023 | ★☆☆☆☆ |
| sex determination (XO grasshopper); Turner's syndrome asked 1× | Board 2023 | ★☆☆☆☆ |
Molecular Basis of Inheritance · Genetics and Evolution
| DNA structure - Chargaff's rule numerical asked 2× | Sample 2023Sample 2027 | ★★★☆☆ |
| lac operon structure and induction asked 2× | Board 2023Sample 2027 | ★★★☆☆ |
| transcription in prokaryotes - sigma and rho factors asked 1× | Sample 2027 | ★★☆☆☆ |
| genetic code - degeneracy, universality; anticodon asked 1× | Sample 2027 | ★★☆☆☆ |
| genetic code - degeneracy asked 1× | Sample 2026 | ★★☆☆☆ |
| DNA structure - Chargaff's rule asked 1× | Sample 2026 | ★★☆☆☆ |
| Griffith's transformation experiment; transcription unit asked 1× | Sample 2026 | ★★☆☆☆ |
| lac operon - regulation of gene expression asked 1× | Sample 2026 | ★★☆☆☆ |
| genetic code - stop codons / translation asked 1× | Sample 2025 | ★☆☆☆☆ |
| structure of tRNA (clover-leaf model) asked 1× | Sample 2025 | ★☆☆☆☆ |
| DNA packaging - nucleosome structure asked 1× | Sample 2025 | ★☆☆☆☆ |
| DNA structure - length calculation asked 1× | Sample 2024 | ★☆☆☆☆ |
| genetic code, transcription, translation and point mutation asked 1× | Sample 2024 | ★☆☆☆☆ |
| DNA replication - requirements of DNA polymerase asked 1× | Board 2026 | ★☆☆☆☆ |
| genetic code - Severo Ochoa (polynucleotide phosphorylase) asked 1× | Board 2026 | ★☆☆☆☆ |
| DNA fingerprinting - VNTR / band matching asked 1× | Board 2026 | ★☆☆☆☆ |
| transcription and post-transcriptional processing (splicing, capping, tailing) asked 1× | Board 2026 | ★☆☆☆☆ |
| transcription in prokaryotes asked 1× | Sample 2023 | ★☆☆☆☆ |
| DNA replication - single strand binding proteins asked 1× | Board 2025 | ★☆☆☆☆ |
| transcription - template vs coding strand polarity asked 1× | Board 2025 | ★☆☆☆☆ |
| DNA structure - Chargaff's rule and base pairing asked 1× | Board 2025 | ★☆☆☆☆ |
| genetic code - degeneracy / codons asked 1× | Board 2024 | ★☆☆☆☆ |
| Griffith's transformation experiment asked 1× | Board 2024 | ★☆☆☆☆ |
| DNA replication - S phase asked 1× | Board 2023 | ★☆☆☆☆ |
Evolution · Genetics and Evolution
| Hardy-Weinberg principle - numerical asked 2× | Board 2024Sample 2027 | ★★★☆☆ |
| analogous organs - convergent evolution asked 2× | Board 2025Sample 2026 | ★★★☆☆ |
| types of natural selection - stabilising, directional, disruptive asked 1× | Sample 2027 | ★★☆☆☆ |
| adaptive radiation - Darwin's finches asked 1× | Sample 2026 | ★★☆☆☆ |
| Hardy-Weinberg numerical; human evolution asked 1× | Sample 2026 | ★★☆☆☆ |
| embryological evidence of evolution asked 1× | Sample 2025 | ★☆☆☆☆ |
| allele and genotype frequency (Hardy-Weinberg) asked 1× | Sample 2025 | ★☆☆☆☆ |
| evidences of evolution - homologous vs analogous asked 1× | Sample 2024 | ★☆☆☆☆ |
| Hardy-Weinberg equilibrium - numerical asked 1× | Sample 2024 | ★☆☆☆☆ |
| evidences of evolution asked 1× | Sample 2024 | ★☆☆☆☆ |
| origin of life - oxidising vs reducing atmosphere asked 1× | Sample 2023 | ★☆☆☆☆ |
| human evolution - hominid ancestors and cranial capacity asked 1× | Sample 2023 | ★☆☆☆☆ |
| Hardy-Weinberg equilibrium; genetic drift / bottleneck asked 1× | Board 2025 | ★☆☆☆☆ |
| types of natural selection - disruptive asked 1× | Board 2024 | ★☆☆☆☆ |
| Malthus - population pressure / natural selection asked 1× | Board 2023 | ★☆☆☆☆ |
| vestigial organs - evidence of evolution asked 1× | Board 2023 | ★☆☆☆☆ |
| Hardy-Weinberg principle and equation asked 1× | Board 2023 | ★☆☆☆☆ |
Human Health and Diseases · Biology and Human Welfare
| interferons - antiviral proteins asked 2× | Sample 2024Sample 2027 | ★★★☆☆ |
| life cycle of Plasmodium / malaria asked 2× | Board 2023Sample 2027 | ★★★☆☆ |
| allergy - histamine release from mast cells asked 1× | Sample 2027 | ★★☆☆☆ |
| drug abuse - cocaine interferes with dopamine transport asked 1× | Sample 2027 | ★★☆☆☆ |
| cancer - metastasis (malignant tumour) asked 1× | Sample 2027 | ★★☆☆☆ |
| fungal disease - ringworm (Trichophyton / Microsporum / Epidermophyton) asked 1× | Sample 2026 | ★★☆☆☆ |
| disease vectors (Anopheles) asked 1× | Sample 2026 | ★★☆☆☆ |
| AIDS - HIV load and helper T-cell decline asked 1× | Sample 2026 | ★★☆☆☆ |
| pathogens - plague, pneumonia, filariasis asked 1× | Sample 2026 | ★★☆☆☆ |
| alcohol abuse - causes and prevention asked 1× | Sample 2026 | ★★☆☆☆ |
| NACO - AIDS control asked 2× | Board 2023Board 2024 | ★★☆☆☆ |
| immunity - antibody secreted by plasma cells asked 1× | Sample 2025 | ★☆☆☆☆ |
| immunity - Mucosal Associated Lymphoid Tissue asked 1× | Sample 2025 | ★☆☆☆☆ |
| cell-mediated immunity - graft rejection asked 1× | Sample 2025 | ★☆☆☆☆ |
| malaria - symptoms asked 1× | Sample 2024 | ★☆☆☆☆ |
| immunity - active and passive types asked 1× | Sample 2024 | ★☆☆☆☆ |
| AIDS - reverse transcriptase in HIV replication asked 1× | Sample 2024 | ★☆☆☆☆ |
| vaccination - Measles Mumps Rubella asked 1× | Sample 2024 | ★☆☆☆☆ |
| structure of antibody - antigen binding site asked 1× | Sample 2024 | ★☆☆☆☆ |
| bacterial pathogen - pneumonia (Streptococcus pneumoniae) asked 1× | Board 2026 | ★☆☆☆☆ |
| disease vectors (rat flea - Xenopsylla) asked 1× | Board 2026 | ★☆☆☆☆ |
| filariasis (elephantiasis) - lymphatic blockage asked 1× | Board 2026 | ★☆☆☆☆ |
| autoimmunity - myasthenia gravis asked 1× | Board 2026 | ★☆☆☆☆ |
| fungal disease - ringworm (Trichophyton / Microsporum) asked 1× | Board 2026 | ★☆☆☆☆ |
| interferons / cytokines in immunity asked 1× | Board 2026 | ★☆☆☆☆ |
| AIDS - HIV destroys helper T-cells asked 1× | Board 2026 | ★☆☆☆☆ |
| drug abuse - cannabinoids (Cannabis sativa) asked 1× | Board 2026 | ★☆☆☆☆ |
| immunity - primary and secondary immune response asked 1× | Board 2026 | ★☆☆☆☆ |
| life cycle of Plasmodium - erythrocytic cycle asked 1× | Board 2026 | ★☆☆☆☆ |
| malaria - haemozoin toxin asked 1× | Sample 2023 | ★☆☆☆☆ |
| immunity - features of neutrophils and B-lymphocytes asked 1× | Sample 2023 | ★☆☆☆☆ |
| passive immunity - tetanus antitoxin asked 1× | Sample 2023 | ★☆☆☆☆ |
| cancer - normal vs cancer cells asked 1× | Sample 2023 | ★☆☆☆☆ |
| allergy - mast cells and IgE asked 1× | Sample 2023 | ★☆☆☆☆ |
| allergy / contact hypersensitivity asked 1× | Board 2025 | ★☆☆☆☆ |
| drug abuse - cannabinoids from Cannabis asked 1× | Board 2025 | ★☆☆☆☆ |
| cancer - benign and malignant tumours asked 1× | Board 2025 | ★☆☆☆☆ |
| AIDS - HIV replication cycle asked 1× | Board 2025 | ★☆☆☆☆ |
| antibody types - IgE and allergy asked 1× | Board 2024 | ★☆☆☆☆ |
| interferons - antiviral (viral infection) asked 1× | Board 2024 | ★☆☆☆☆ |
| primary and secondary lymphoid organs asked 1× | Board 2024 | ★☆☆☆☆ |
| pathogens - causative agents and transmission asked 1× | Board 2024 | ★☆☆☆☆ |
| AIDS - HIV replication and diagnosis asked 1× | Board 2024 | ★☆☆☆☆ |
| protozoan pathogens (Entamoeba) asked 1× | Board 2023 | ★☆☆☆☆ |
| antibody types (IgG); passive immunity asked 1× | Board 2023 | ★☆☆☆☆ |
| passive immunity / anti-tetanus antiserum asked 1× | Board 2023 | ★☆☆☆☆ |
| lymphocyte maturation sites; sources of drugs of abuse asked 1× | Board 2023 | ★☆☆☆☆ |
| communicable / airborne diseases (pneumonia) asked 1× | Board 2023 | ★☆☆☆☆ |
Microbes in Human Welfare · Biology and Human Welfare
| biofertilisers - symbiotic Rhizobium in legume root nodules asked 1× | Sample 2027 | ★★☆☆☆ |
| biogas plant - KVIC asked 1× | Sample 2027 | ★★☆☆☆ |
| industrial products - antibiotics (penicillin: Chain and Florey) asked 1× | Sample 2027 | ★★☆☆☆ |
| biogas - methane and methanogens asked 1× | Sample 2027 | ★★☆☆☆ |
| biofertilisers - cyanobacteria / Azolla asked 1× | Sample 2026 | ★★☆☆☆ |
| industrial products - fermented beverages (Saccharomyces) asked 1× | Sample 2026 | ★★☆☆☆ |
| biofertilisers - cyanobacteria / nitrogen-fixing bacteria asked 1× | Sample 2025 | ★☆☆☆☆ |
| biocontrol - Bacillus thuringiensis toxin specificity asked 1× | Sample 2025 | ★☆☆☆☆ |
| biocontrol agents and target pests asked 1× | Sample 2025 | ★☆☆☆☆ |
| bioactive molecules - statins, cyclosporin-A asked 1× | Sample 2025 | ★☆☆☆☆ |
| biogas production - spent slurry asked 1× | Sample 2024 | ★☆☆☆☆ |
| cyclosporin-A - immunosuppressant from microbes asked 1× | Sample 2024 | ★☆☆☆☆ |
| biogas - methanogens and benefits asked 1× | Sample 2024 | ★☆☆☆☆ |
| biocontrol agents (ladybird) / IPM asked 1× | Board 2026 | ★☆☆☆☆ |
| biogas production asked 1× | Sample 2023 | ★☆☆☆☆ |
| biocontrol agents - Trichoderma and Baculovirus asked 1× | Sample 2023 | ★☆☆☆☆ |
| industrial products - fermented beverages asked 1× | Sample 2023 | ★☆☆☆☆ |
| biofertilisers - cyanobacteria / Rhizobium asked 1× | Board 2025 | ★☆☆☆☆ |
| microbes in household products - curd, cheese asked 1× | Board 2025 | ★☆☆☆☆ |
| sewage treatment - primary and secondary asked 1× | Board 2025 | ★☆☆☆☆ |
| industrial enzymes - pectinase in juice clarification asked 1× | Board 2024 | ★☆☆☆☆ |
| industrial products - streptokinase clot buster asked 1× | Board 2024 | ★☆☆☆☆ |
| microbes in household and industrial products asked 1× | Board 2024 | ★☆☆☆☆ |
| sewage treatment and BOD asked 1× | Board 2023 | ★☆☆☆☆ |
Biotechnology: Principles and Processes · Biotechnology and its Applications
| restriction enzyme nomenclature asked 3× | Board 2026Sample 2026Sample 2027 | ★★★★★ |
| palindromic recognition sequence; reverse transcription asked 2× | Sample 2025Sample 2027 | ★★★★☆ |
| insertional inactivation - pBR322 selectable markers asked 2× | Sample 2025Sample 2027 | ★★★★☆ |
| insertional inactivation - blue-white selection asked 2× | Board 2025Sample 2023 | ★★☆☆☆ |
| cloning vectors for eukaryotes - Ti plasmid and disarmed retroviruses asked 1× | Sample 2027 | ★★☆☆☆ |
| methods of transfer of rDNA - biolistics / gene gun asked 1× | Sample 2027 | ★★☆☆☆ |
| cloning vectors - pBR322 and Agrobacterium (Ti plasmid) asked 1× | Sample 2027 | ★★☆☆☆ |
| PCR - number of molecules after cycles asked 1× | Sample 2026 | ★★☆☆☆ |
| gel electrophoresis - anode migration and ethidium bromide asked 1× | Sample 2026 | ★★☆☆☆ |
| restriction enzymes; gel electrophoresis of circular vs linear DNA asked 1× | Sample 2026 | ★★☆☆☆ |
| PCR - number of amplification cycles asked 1× | Sample 2025 | ★☆☆☆☆ |
| cloning vector - single restriction site requirement asked 1× | Sample 2025 | ★☆☆☆☆ |
| gel electrophoresis interpretation; blue-white selection asked 1× | Sample 2025 | ★☆☆☆☆ |
| selection of recombinants - antibiotic resistance / insertional inactivation asked 1× | Sample 2024 | ★☆☆☆☆ |
| discovery of restriction enzymes asked 1× | Sample 2024 | ★☆☆☆☆ |
| restriction digestion and gel electrophoresis interpretation asked 1× | Sample 2024 | ★☆☆☆☆ |
| bioreactors - stirred tank vs sparged asked 1× | Board 2026 | ★☆☆☆☆ |
| cloning vectors - selectable markers and YAC asked 1× | Board 2026 | ★☆☆☆☆ |
| bioreactors - sparged / air-lift asked 1× | Sample 2023 | ★☆☆☆☆ |
| restriction enzymes - palindromic recognition sequence asked 1× | Sample 2023 | ★☆☆☆☆ |
| Cohen - recombinant DNA technology asked 1× | Sample 2023 | ★☆☆☆☆ |
| Boyer - recombinant DNA technology / restriction enzyme asked 1× | Sample 2023 | ★☆☆☆☆ |
| PCR - gene amplification asked 1× | Sample 2023 | ★☆☆☆☆ |
| stirred-tank bioreactor structure asked 1× | Sample 2023 | ★☆☆☆☆ |
| restriction enzyme nomenclature (EcoRV) asked 1× | Board 2025 | ★☆☆☆☆ |
| source of Taq polymerase (Thermus aquaticus) asked 1× | Board 2025 | ★☆☆☆☆ |
| transformation - transgene expression and bacterial growth asked 1× | Board 2025 | ★☆☆☆☆ |
| restriction enzymes - blunt and sticky ends asked 1× | Board 2025 | ★☆☆☆☆ |
| bioreactors - sterile conditions asked 1× | Board 2024 | ★☆☆☆☆ |
| gel electrophoresis - ethidium bromide staining asked 1× | Board 2024 | ★☆☆☆☆ |
| features of a good cloning vector (ori, selectable markers) asked 1× | Board 2024 | ★☆☆☆☆ |
| PCR - Taq polymerase source asked 1× | Board 2023 | ★☆☆☆☆ |
| PCR - primers asked 1× | Board 2023 | ★☆☆☆☆ |
| role of ligase in rDNA asked 1× | Board 2023 | ★☆☆☆☆ |
| competent cells / transformation of host asked 1× | Board 2023 | ★☆☆☆☆ |
| gel electrophoresis asked 1× | Board 2023 | ★☆☆☆☆ |
| pBR322 cloning vector - restriction sites and selectable markers asked 1× | Board 2023 | ★☆☆☆☆ |
Biotechnology and its Applications · Biotechnology and its Applications
| molecular diagnosis - ELISA principle (antigen-antibody interaction) asked 1× | Sample 2027 | ★★☆☆☆ |
| micropropagation / plant tissue culture asked 1× | Sample 2027 | ★★☆☆☆ |
| Bt crops - source of Bt toxin (Bacillus thuringiensis) asked 1× | Sample 2026 | ★★☆☆☆ |
| GEAC; alpha-1-antitrypsin (transgenic products) asked 1× | Sample 2026 | ★★☆☆☆ |
| insulin chains - protein sequencing (Sanger) asked 1× | Sample 2025 | ★☆☆☆☆ |
| molecular diagnosis - ELISA / PCR for HIV asked 1× | Sample 2025 | ★☆☆☆☆ |
| RNA interference (RNAi) - Meloidogyne incognita asked 1× | Sample 2024 | ★☆☆☆☆ |
| Bt crops - pest resistance asked 1× | Sample 2024 | ★☆☆☆☆ |
| transgenic animals for bioactive products asked 1× | Sample 2024 | ★☆☆☆☆ |
| RNA interference - pest resistance asked 1× | Board 2026 | ★☆☆☆☆ |
| gene therapy for SCID - non-permanent cure asked 1× | Board 2026 | ★☆☆☆☆ |
| genetically engineered human insulin (Humulin) asked 1× | Board 2026 | ★☆☆☆☆ |
| human insulin - disulphide bond between chains asked 1× | Sample 2023 | ★☆☆☆☆ |
| molecular diagnosis - PCR / ELISA for HIV asked 1× | Sample 2023 | ★☆☆☆☆ |
| biopiracy (Basmati, turmeric) asked 1× | Board 2025 | ★☆☆☆☆ |
| Bt crops - cry genes and target pest (cotton bollworm) asked 1× | Board 2024 | ★☆☆☆☆ |
| gene therapy - ADA deficiency (SCID) asked 1× | Board 2024 | ★☆☆☆☆ |
| production of human insulin (proinsulin processing) asked 1× | Board 2024 | ★☆☆☆☆ |
| Bt toxin activation - alkaline gut pH asked 1× | Board 2023 | ★☆☆☆☆ |
| gene therapy for ADA-deficiency (SCID) asked 1× | Board 2023 | ★☆☆☆☆ |
Organisms and Populations · Ecology and Environment
| age pyramids - expanding, stable, declining asked 3× | Board 2023Sample 2026Sample 2027 | ★★★★★ |
| population growth models - logistic / sigmoid curve asked 2× | Board 2026Sample 2027 | ★★★☆☆ |
| population interactions - amensalism asked 1× | Sample 2027 | ★★☆☆☆ |
| population attributes - population density asked 1× | Sample 2027 | ★★☆☆☆ |
| predator-prey population dynamics asked 1× | Sample 2027 | ★★☆☆☆ |
| population density (natality, mortality, migration); carrying capacity asked 1× | Sample 2026 | ★★☆☆☆ |
| competition - competitive exclusion and competitive release asked 1× | Sample 2025 | ★☆☆☆☆ |
| population interactions - commensalism asked 1× | Sample 2024 | ★☆☆☆☆ |
| population density - natality, mortality, migration asked 1× | Sample 2024 | ★☆☆☆☆ |
| population interactions - mutualism (mycorrhiza) asked 1× | Sample 2024 | ★☆☆☆☆ |
| population interactions - types of parasitism asked 1× | Sample 2024 | ★☆☆☆☆ |
| population attributes - mortality calculation asked 1× | Board 2026 | ★☆☆☆☆ |
| population growth rate (natality, mortality, immigration, emigration) asked 1× | Board 2026 | ★☆☆☆☆ |
| competition - Gause's competitive exclusion principle asked 1× | Board 2026 | ★☆☆☆☆ |
| population growth rate calculation asked 1× | Board 2025 | ★☆☆☆☆ |
| logistic growth model asked 1× | Board 2025 | ★☆☆☆☆ |
| population interactions - parasitism types asked 1× | Board 2025 | ★☆☆☆☆ |
| population interactions - commensalism (epiphyte) asked 1× | Board 2024 | ★☆☆☆☆ |
| population attributes - natality calculation asked 1× | Board 2024 | ★☆☆☆☆ |
| population growth models - exponential and logistic asked 1× | Board 2024 | ★☆☆☆☆ |
| plant chemical defence against herbivory (cardiac glycosides) asked 1× | Board 2023 | ★☆☆☆☆ |
Ecosystem · Ecology and Environment
| productivity - NPP = GPP - respiration asked 3× | Board 2025Sample 2024Sample 2027 | ★★★★☆ |
| ecological pyramids - pyramid of biomass asked 2× | Board 2023Sample 2027 | ★★★☆☆ |
| ecological pyramids - inverted pyramid of numbers asked 1× | Sample 2026 | ★★☆☆☆ |
| productivity - Net Primary Productivity asked 1× | Sample 2026 | ★★☆☆☆ |
| decomposition - detritus quality (chitin) asked 1× | Sample 2026 | ★★☆☆☆ |
| ecological pyramids - pyramid of energy and 10% law asked 1× | Sample 2026 | ★★☆☆☆ |
| decomposition - detritivores and fragmentation asked 1× | Sample 2025 | ★☆☆☆☆ |
| ecological pyramids; energy flow - 10% law asked 1× | Sample 2025 | ★☆☆☆☆ |
| energy flow - 10% law asked 1× | Board 2026 | ★☆☆☆☆ |
| standing state asked 1× | Sample 2023 | ★☆☆☆☆ |
| productivity - GPP = NPP + respiration asked 1× | Sample 2023 | ★☆☆☆☆ |
| ecological pyramids - inverted pyramid of number asked 1× | Sample 2023 | ★☆☆☆☆ |
| ecological pyramids and 10% law asked 1× | Board 2025 | ★☆☆☆☆ |
| R. Misra - Father of Indian Ecology asked 1× | Board 2025 | ★☆☆☆☆ |
| energy flow; photosynthetically active radiation asked 1× | Board 2025 | ★☆☆☆☆ |
| decomposition and productivity (GPP = NPP + R) asked 1× | Board 2024 | ★☆☆☆☆ |
| R. Misra - father of ecology in India asked 1× | Board 2023 | ★☆☆☆☆ |
| decomposition - fragmentation, leaching, catabolism, humification, mineralization asked 1× | Board 2023 | ★☆☆☆☆ |
Biodiversity and its Conservation · Ecology and Environment
| species-area relationship - numerical asked 2× | Board 2024Sample 2025 | ★★☆☆☆ |
| global biodiversity - proportion of invertebrate groups asked 1× | Sample 2027 | ★★☆☆☆ |
| Rivet Popper Hypothesis asked 1× | Sample 2027 | ★★☆☆☆ |
| patterns of biodiversity - latitudinal gradients asked 1× | Sample 2026 | ★★☆☆☆ |
| in-situ and ex-situ conservation; cryopreservation asked 1× | Sample 2026 | ★★☆☆☆ |
| causes of biodiversity loss asked 1× | Sample 2025 | ★☆☆☆☆ |
| ex-situ conservation - captive breeding asked 1× | Sample 2025 | ★☆☆☆☆ |
| biodiversity and causes of its loss asked 1× | Sample 2024 | ★☆☆☆☆ |
| loss of biodiversity - habitat loss asked 1× | Board 2026 | ★☆☆☆☆ |
| species-area relationship (Alexander von Humboldt) asked 1× | Board 2026 | ★☆☆☆☆ |
| Ramsar sites - wetland conservation asked 1× | Sample 2023 | ★☆☆☆☆ |
| ex-situ conservation methods asked 1× | Sample 2023 | ★☆☆☆☆ |
| species-area relationship; Rivet Popper Hypothesis asked 1× | Sample 2023 | ★☆☆☆☆ |
| Red Data Book asked 1× | Board 2025 | ★☆☆☆☆ |
| Earth Summit - biodiversity conservation asked 1× | Board 2025 | ★☆☆☆☆ |
| Rivet Popper Hypothesis; importance of biodiversity asked 1× | Board 2025 | ★☆☆☆☆ |
| ex-situ conservation - cryopreservation asked 1× | Board 2023 | ★☆☆☆☆ |
| causes of biodiversity loss (The Evil Quartet) asked 1× | Board 2023 | ★☆☆☆☆ |
Importance = how often a topic was asked × how recent, with extra weight for the latest official sample paper.