Main Points

Our Environment

  • Substances which are broken down by biological processes are called biodegradable substances.
  • Substances which are not broken down by biological processes are called non-biodegradable substances.
  • The system of interaction among living and non-living in a geographical area is called ecosystem.
  • The non-living things in an ecosystem comprise the abiotic component.
  • The living beings in an ecosystem comprise the biotic component.
  • Organisms which make their own food are called producers.
  • Organisms which obtain food from producers are called consumers.
  • Organisms which degrade the remains of living beings are called decomposers.
  • The chain of predator and prey is called a food chain.
  • A complex network of many food chains is called a food web.
  • The flow of energy is unidirectional through a food chain.
  • At any trophic level, 90% of the total energy consumed is utilized by the organism, and just 10% of the total energy consumed is available for the consumption of organism at the next trophic level.
  • The ozone layer forms a protective shield because it prevents the harmful ultraviolet radiations from entering the troposphere.
  • In the 1980s, the amount of ozone began to fall drastically. This happened because of excess use of CFCs (Chlorofluorocarbon).

These main points are highly helpful for last minute preparation for examination. You can glance through them while going for examination. You can view them in the school bus, in car, in elevator, etc.