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atmosphereatmosphere is an envelope of the most useful gases that cover the planet earth it makes our planet unique and enables life to prosper if
ecological crises in oceans and coasts coastal and marine areas all over the world including those in india are under stress because two thirds of
availability of nutrientsthe nutrients in the upper layers of water are constantly being taken up by the phytoplankton who are the
some physical features of the oceansthe oceans are so vast that they stagger ones imagination they cover more than 70 per cent of the earths
interaction in the earth ecosystemin this comparatively smaller section we will give you the idea that the earth as a whole is an ecosystem
intrusion into the water cyclewater management is one of the leading concerns of man today the natural water cycle has not been able to
intrusion into the carbon cycle in the carbon cycle as long as the average amount of carbon dioxide hair and in water remains the same a
intrusion into the nitrogen cyclehuman intervention can disturb the nitrogen cycle let us see how when we grow and harvest crops there is loss
cycling of materials in ecosystemliving organisms require four nutrients in relatively large amounts these are carbon oxygen nitrogen and hydrogen
respiration food oxygen -gt carbon dioxide water energy food is not only a source of energy but also the nutrients used to build
photosynthesiscarbon dioxide water solar energy minerals -gt food oxygenfood made during photosynthesis may later be used for energy by
ecology and environmenttoday we hear people from different walks of life using the terms ecology and environment politicians leaders town
anthropological evidencemodern humans arose at a time when the earth was going through a very cold and icy period called the ice age which began
archaeological evidencethe study of human antiquities especially of prehistoric period is known as archaeology the biological and cultural
australopithecus-the transitional human formsby about two million years ago there were several well established hominid ancestors in africa one of
palaeontological evidencepalaeontology is a branch of earth sciences which is essentially a study of plant and animal life in the past
theories of evolution of mantowards the beginning of the nineteenth century scientists had already started doubting the theory of special
chemical evolutionthe question of how life came into being in the first place still remained unanswered to find an answer to this
origin of life on the earthman has always wondered how he came into existence who created him and why he was created curiosity in this
plutoplutos existence was also proposed to account for deviations in the orbit of uranus even after the influence of neptunehad been
neptunethe eigth planet neptune was discoveted in 1846 by astronomer johann gottfried galle we have already told you the story of
the asteroid belt-rubble of the solar systemthere is a gap of 547 million kilometers between the orbits of mars and jupiter in this gap are
solar wind and solar flaremost of the suns family is continually bathed in an outflow of material from the suns atmosphere streams of
evidence favouring the big bangone piece of evidence comes from the expansion of the universe which we have already described the expanding
big bang theorythe most important current theory for the origin of the universe is the big bang theoryaccording to this theory the