Current Affairs 10th Class

Category : 10th Class

 Our Environment

• Environment is the physical and biological world we live in. Biosphere is the total sum of all ecosystems.

• A community is a group of different kinds of animal and plant populations living together in a given area.

• An ecosystem is defined as a group of organisms interacting among themselves and with their environment.

• The biotic components of an ecosystem include producers, consumers and decomposers.

• Organisms which feed upon plants consumer animals for food are called e.g., herbivores and carnivores.                                

• Decomposers are organisms which bring about the decay and putrefaction of the dead bodies of plants and animals.

• A food chain is a sequence of organisms that feed on one another and consists of producers, primary, secondary and tertiary consumers. Several food chains are linked together to form a food web.

• The ultimate source of energy for an ecosystem is the Sun. The total energy available at each level in an ecosystem is called tropic level.

• The organic molecules formed in plants are partly used in catabolic processes and the rest are stored in the body in the form of biomass. The storage of energy in this form is called gross or net primary productivity.

• The number of individuals of different tropic levels is called ecological pyramid.

• Ecological pyramids are of three types: pyramid of numbers, pyramid of energy and pyramid of biomass.

• Pollution is the undesirable change in the physical, chemical and biological constituents of air, water and soil. It is of different types: air pollution, water pollution, soil or land pollution, noise pollution, radiation pollution and thermal pollution.

• Hydrocarbons emitted in huge quantities by the burning of petrol in the automobiles combine with\[N{{O}_{2}}\]and produce photochemical smog.

• \[S{{O}_{2}}\]and\[N{{O}_{2}}\]combine with the water vapours present in the air to form acid rains which affect both flora and fauna due to air pollution.

• Ozone layer protect us from UV rays.

• Chlorofluorocarbons lead to ozone layer depletion.

• The excess of \[C{{O}_{2}}\]present in air leads to greenhouse effect thus leading to global warming (increase in the average temperature of the earth).