OUR ENVIRONMENT

 

OUR ENVIRONMENT

 Environment – The surrounding of any living organism is termed as its Environment.

 Enzymes – Enzymes are particular chemicals which convert the complex molecules into simpler ones. 

Biodegradable substances	Non-biodegradable substances
Substances that can be broken down into simpler molecules by the action of enzymes are biodegradable substances. Egs. Kitchen wastes, paper, leaves, etc. These substances do not prove harmful to the environment. Instead enriches the fertility of the soil after its decomposition.	Substances that cannot be broken down into simpler form are called Non-biodegradable substance. Egs. Glass, plastic, etc These substances persist in the environment for a long time and harm the members of ecosystem.

 Ecosystem – The interaction between the living and non-living components of the environment constitutes an Ecosystem.

 Components of ecosystem

Biotic Components	Abiotic Components
Living components of the ecosystem are called biotic components Egs. Plants, animals, microorganisms	Non living components of the ecosystem are called abiotic components Egs soil, sunlight, rainfall, temperature

 Natural ecosystems – Forests, ponds, lakes, etc

Artificial ecosystem – garden, crop fields, etc

 

Producers	Consumers	Decomposers
Organisms which produce their own food are called producers. Egs. Green plants, blue green algae	Organisms which depend on producers directly or indirectly for their food are called consumers. Egs. Herbivores and carnivores.	Organisms that decompose the dead and decaying matter are called as decomposers. Egs microorganisms

 

Food Chain: The transfer of food energy from one tropic level to another is called food chain.

Primary Consumers(Herbivores): The animals which obtain their food energy directly by feeding on Plants. Eg. Grasshopper, Deer, cattle.

Secondary Consumers: The animals which depend on herbivores for their food. Eg. Frog, Lion, Tiger.

Tertiary Consumer: The animals which obtain their food by feeding on secondary consumers. Eg. Snake

Ecological Pyramids: Graphical representations of the successive tropic levels and the relation among them are called as “Ecological pyramids”

 Food web: Complex network of interconnected food chain, forms a food web.

Ø  Energy flow is unidirectional.

Ø  Only 10% of the energy available at any tropic level is getting transferred to next level.

Bio magnification / Biological magnification: Increase in concentration of toxic substance from one tropic level to another.

 Environmental Problems

1)     Depletion of Ozone layer

2)     Garbage disposal

 Depletion of Ozone layer

Ozone (O3) – This formed by 3 atoms of oxygen.

This is deadly poisonous.

This filters the harmful UV radiations. (UV radiations causes skin cancer)

Depletion of Ozone – the reason for the depletion of ozone layer is the use of the synthetic chemicals like chlorofluorocarbon (CFC)

 Garbage disposal

This is one of the major problems we face now-a-days.

Improvement in our life style is resulting in generation of more waste material.

Use of disposable things and changes in the packaging system is resulting in generation of non-biodegradable wastes