Nagaland Board Class 12th Biology Syllabus 2025-26: Download PDF Below

Unit No.

Unit Name

Expanded Description of Topics

Marks

I

Reproduction

This unit begins with Reproduction in Organisms, describing asexual and sexual modes of reproduction. In Sexual Reproduction in Flowering Plants, students study floral structures, development of male and female gametophytes, pollination (types, agents, adaptations), double fertilization, formation of seeds and fruits, and apomixis. In Human Reproduction, topics include the male and female reproductive systems, gametogenesis (spermatogenesis and oogenesis), menstrual cycle, fertilization, embryonic development, parturition, and lactation. Reproductive Health introduces contraceptive methods, assisted reproductive technologies (ARTs), and population control measures.

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II

Genetics and Evolution

This section covers the fundamental principles of heredity and variation. Principles of Inheritance and Variation includes Mendel’s experiments, laws of inheritance, deviations from Mendelian ratios, incomplete dominance, codominance, multiple alleles, blood groups, pleiotropy, polygenic inheritance, and chromosomal theory of inheritance. Molecular Basis of Inheritance includes structure of DNA and RNA, replication, transcription, translation, genetic code, regulation of gene expression, human genome project, and DNA fingerprinting. Evolution deals with origin of life, theories of evolution (Darwinism, Lamarckism, modern synthetic theory), evidences for evolution, Hardy-Weinberg principle, adaptive radiation, and human evolution.

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III

Biology in Human Welfare

This unit explores the role of biology in improving health, food production, and environment. Human Health and Disease covers common infectious diseases (malaria, amoebiasis, ascariasis, filariasis, ringworm, etc.), immunity (innate and acquired), vaccines, AIDS, cancer, allergies, and drug/alcohol abuse. Strategies for Enhancement in Food Production includes improvement in crops and livestock, plant breeding, tissue culture, single-cell proteins, and biofortification. Microbes in Human Welfare covers industrial use of microbes (antibiotics, beverages, enzymes), sewage treatment, biogas production, and biocontrol agents.

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IV

Biotechnology and Its Applications

This section introduces Principles and Processes of Biotechnology, including genetic engineering, recombinant DNA technology, cloning vectors, and steps involved in gene transfer. Applications include genetically modified organisms (GMOs), transgenic animals, biopharmaceuticals (insulin, vaccines), gene therapy, DNA fingerprinting, and bioethics. Students also study the impact of biotechnology on agriculture (Bt crops, pest-resistant plants) and medicine.

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V

Ecology and Environment

Ecology explains the interactions between organisms and their environment. Organisms and Populations discusses population growth models, adaptations, population interactions (predation, competition, symbiosis). Ecosystem covers ecosystem structure, productivity, decomposition, energy flow, ecological pyramids, nutrient cycles, and ecological succession. Biodiversity and Conservation explains genetic, species, and ecosystem diversity, patterns of biodiversity, hotspots, threats to biodiversity, conservation methods (in situ and ex situ). Environmental Issues include air pollution, water pollution, deforestation, ozone depletion, global warming, and solid waste management.

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