Applicable for A-Level, IB, DSE, AP-Level Exams

Biological Molecules    Cell Structure    Cell Transport    Immunology    Exchange    Mass Transport    DNA, Genes & Protein Synthesis    Genetic Diversity    Biodiversity    Photosynthesis    Respiration    Energy & Ecosystems    Stimuli and Response    Nervous Coordination & Muscles    Homeostasis    Inheritance    Populations & Evolution    Ecosystems    Gene Expression    Recombinant DNA Technology   


A community and the non-living components of its environment together form an ecoysystem. Am ecpsystem supports a certain size of population of a species, called the carrying capcity. An ecosystem's population size can vary due to the effect of abiotic factors as well as interactions between organisms.

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Succession is the process by which an ecosystem changes over time. Succession occurs as pioneer species like microscopic plants die and decompose. This changes the environment such as it increases amount of organic matter. New species colonise once there is a change as there is an increase in biomass, nutrient availability and species. A climax community is finally formed with more stability and change from extreme conditions.

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