Biology Grade 12 

25.1 Ecosystem 25.1.1 Biosphere 25.1.2 Autecology 25.1.3 Synecology

25.2 Components of Ecosystem 25.2.1 Biotic Components 25.2.2 Abiotic Components

25.3 Succession 25.3.1 Two Major forms of Succession 25.3.2 Predation and its Significance 25.3.3 Parasitism and its Significance 25.3.4 Symbiosis 25.3.5 Mutualism 25.3.6 Commensalism 25.3.7 Grazing

25.4 Biogeochemical Cycles 25.4.1 The Nitrogen Cycle 25.4.2 Nitrogen Deplition and its Remedies 25.4.3 The Flow of Energy in Food Chain of an Ecosystem