Definition, relevance, principles and scope of ecology, sub-divisions, Structure and functions, biotic and abiotic components and productivity of ecosystem and energy flow, materials cycling, energetics, limiting factors, development and evolution; Trophic levels, food chain and food webs, ecological pyramids, competition, population ecology ; Lakes, wetlands and rivers, reservoirs and springs, structure and functions, usefulness, natural and manmade ecosystems; concept, importance and conservation of aquatic biodiversity role of invasive species and its importance; System analysis, ecosystem models, Stressed ecosystems, homeostasis, ecological succession, ecosystem resilience; Pollution of lakes and rivers, causes, impacts and control of eutrophication; principles and application of restoration methods, ecotechnologies ; National/international perspectives, policies, Ramsar convention, NLCP, NRCD, case studies of Dal lake, Nainital lake, Chilka, Loktak and Asan wetlands, Tehri dam reservoir, river Ganges and Yamuna; Elementary biochemistry, salient features of biomolecules, enzymes and other tools of biotechnology, discovery and diversity, prokaryotic cell, microbial energetics, biosynthesis and nutrition, autotrophic way of life, growth, macromolecular synthesis; Microorganism in environment, microbiology of water, bacteria and viruses, bacteriophages, animal and plant viruses, structure, replication and quantification, structure and diversity of algae, protozoa and rotifers;