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NCERT Ebook – Ecosystem
Ecosystem–Structure and Function Productivity Decomposition Energy Flow Ecological Pyramids Ecological Succession Nutrient Cycling Ecosystem Services Chapter 14 Ecosystem 14.1 Ecosystem–Structure and Function 14.2 Productivity 14.3 Decomposition 14.4 Energy Flow 14.5 Ecological Pyramids 14.6 Ecological Succession 14.7 Nutrient Cycling 14.8 Ecosystem Services An ecosystem can be visualised as a functional unit of nature, where living organisms interact among themselves and also with the surrounding physical environment. Ecosystem varies greatly in size from a small pond to a large forest or a sea. Many ecologists regard the entire biosphere as a global ecosystem, as a composite of all local ecosystems on Earth. Since this system is too much big and complex to be studied at one time, it is convenient to divide it into two basic categories, namely the terrestrial and the aquatic. Forest, grassland and desert are some examples of terrestrial ecosystems; pond, lake, wetland, river and estuary are some examples of aquatic ecosystems. Crop fields and an aquarium may also be considered as man-made ecosystems. We will…
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NCERT Ebook – The Living World
What is ‘Living’? Diversity in the Living World Taxonomic Categories Taxonomical Aids Chapter 1 The Living World Chapter 2 Biological Classification Chapter 3 Plant Kingdom Chapter 4 Animal Kingdom Biology is the science of life forms and living processes. The living world comprises an amazing diversity of living organisms. Early man could easily perceive the difference between inanimate matter and living organisms. Early man deified some of the inanimate matter (wind, sea, fire etc.) and some among the animals and plants. A common feature of all such forms of inanimate and animate objects was the sense of awe or fear that they evoked. The description of living organisms including human beings began much later in human history. Societies which indulged in anthropocentric view of biology could register limited progress in biological knowledge. Systematic and monumental description of life forms brought in, out of necessity, detailed systems of identification, nomenclature and classification. The biggest spin off of such studies was the recognition of the sharing of similarities among living organisms both horizontally and vertically. That all present day living organisms are related to each other and also to all organisms that ever lived on this earth, was a revelation which humbled man and led to cultural movements for conservation of biodiversity. In the following chapters of this unit, you will get a description, including classification, of animals and plants from a taxonomist’s perspective. Ernst Mayr(1904 – 2004) Born on 5 July 1904, in Kempten, Germany, Ernst Mayr, the Harvard University evolutionary biologist who has been called ‘The Darwin of the 20th century’, was one of the 100 greatest scientists of all time. Mayr joined Harvard’s Faculty of Arts and Sciences in 1953 and retired in 1975, assuming the title Alexander Agassiz Professor of Zoology Emeritus. Throughout his nearly 80 — year career,his…
