Our Environment

Introduction

     Environment includes all the factors that affect the form and growth of the organism.

Habitat and Adaptations

     Habitat is the term given to the special environment in which an organism lives and grows. In order to survive, plants and animals develop special features called adaptive characters that help them to adjust to a particular habitat. This is known as adaptation.

Adaptation in Plants

     Depending upon the quantity of water available in the habitat, plants undergo modification of their body structures so that they can suitably adapt themselves.

Adaptation in Animals

     Depending upon whether the animal lives on land, water or air, it possesses various structural and functional features which enable it to survive in it's respective habitat.

Habitat Alteration and Conservation

     The habitat and adaptation have a very strong relationship and a perfect balance must be maintained for the survival of the organism. Due to natural calamities and human activities the habitat often gets altered. These alterations may be permanent or temporary.

Biosphere

     Earth is the only planet on which life exists. It consists of three components Lithosphere (Land), Hydrosphere (Water) and Atmosphere (Air). Life originated and evolved because of this unique combination of the three components and was ideal and favourable for life. The life supporting zone of the earth where atmosphere, hydrosphere and lithosphere meet, interact and make life possible, is known as biosphere.

Food Chains and Food Webs

     While studying the biotic components in an ecosystem we have realised that food prepared by green plants is consumed by a series of consumers, both herbivores and carnivores, and finally broken down into their elements and released back into nature by decomposers in nature.

Functions of Ecosystem

     Although matter circulates, energy cannot be reused indefinitely. Solar energy is converted by the photosynthetic producers (plants) into chemical energy in the form of plant carbohydrates. Herbivores consume the plant carbohydrates and so this chemical energy is transferred to them. Carnivores consume herbivores. So the energy is circulated further to the next trophic level. In these animals, this chemical energy is converted mostly into mechanical energy (work done) and heat. The heat is lost to the atmosphere at each trophic level.

Types of Ecosystem

     Biomass is the living matter in any organism. It is the amount of living time or energy available as food for the organisms of the next trophic level. The mass of organisms in each trophic level is called the standing crop.