Showing posts with label Adaptation. Show all posts
Showing posts with label Adaptation. Show all posts

Wednesday, March 30, 2011

Living and the Non-Living organisms, Metabolism, Growth and Development


Living and the Non-Living
If we chemically analyse a living organism, plant or animal, we find that it is made up of carbon, hydrogen, oxygen, nitrogen and a few other elements. However, a mixture of these elements does not make a living organism. Then, how do we define life. It is difficult to arrive at a universal definition of life. Nevertheless, it is possible to characterise living things. We may say that living organisms are those characterised by the following features.

(i) Organisation All living organisms have a definite shape and size as well as physical and chemical composition inherited from their parents. This is possible because of a high degree of organisation. The molecules of which an organism is made up are organised into cells, which in turn are organised into tissues, organs and organ systems making the whole individual. This kind of complex organisation is not found in non-living things.
(ii) Metabolism Green plants obtain their nourishment from the environment in the form of water, carbon dioxide, and certain minerals which are utilised to synthesize carbohydrates during photosynthesis. Carbohydrates are in turn broken down during respiration and the energy thus released is used to synthesize other organic compounds like lipids, proteins, nucleic acids, etc. which make up the body. Animals, bacteria and fungi, on the other hand, obtain nourishment in the form of organic compounds and utilise them to synthesize compounds they need. Such reactions do not occur in non-living objects.
(iii) Growth and Development Living organisms often arise from a single cell which divides and re-divides to form a large number of cells that differentiate into the various organs of the body. These kind of phenomena are not known in the non-living world.
(iv) Reproduction Living organisms, unlike non-living, are universally recognised by their capacity to multiply their own types by means of asexual or sexual reproduction.
(v) Responsiveness All living organisms respond to stimuli, e.g., roots move towards the earth and shoots toward the sun, stomates open during the day and close during the night, and the dog wags its tail on seeing its j master. This kind of response does not occur in the non­living.
(vi) Adaptation    Organisms have the ability to adapt themselves to the needs of the environment which helps j them to survive. For example, plants growing in saline soils have a high-concentration of salts in their body and those in deserts have few leaves with thick waxy coatings. Likewise, animals living in cold climates have a thick coat of hair on the body and a chameleon can change its body colour according to its surroundings.

Saturday, March 26, 2011

Adaptation


Adaptation
Adaptation is the most basis and rather self evident concept. The organism’s are surviving because they are adapted and they are adapted because they are surviving. Since the environment is ever changing , the different organisms should either change accordingly in order to survive in the rigorousof the new circumstances or be ready for extinction. Therefore, a sucession of environmental changes is paralleled by the development of adaptive features, morphological and physiological including food and feeding habit, way of living, defensive mechanism and protection against bad weathers etc.
The fact becomes more evident when use observe the nature and the living organisms all round. Aquatic different organization have common features of possessing paddles like appendages for swimming. The flying animals  all posses wing or wing like structures. It means that the organisms are adopted to their made of life.
Therefore, Adaptation can be defined as “the modification in the body organization or physiology of organisms, which enables them to thrive successfully in a particular environment. So that are able to secure sufficient food , to protect and to reproduce sucessfully for maintaining the continuity of race”.
 In more simple languages “Adaptation is the morphological and physiological modification in an organisms to adjust itself in a particular enviroment”. Since the environment is ever changing, the different organisms should either change accordingly in order to survive in the rigours of the new circumstances or be ready for extinction. Therefore, a succession of environment change is paralleled by the development of adaptive features morphological and physiological including food and feeding habit way of living defensive mechanisms and protection against bad weathers etc.
Jean Baptiste de Lamark first emphasized that animals modify themselves according to the changing environment, Darwin believed that animals are preadopted and seek suitable environment.
Kinds of Adaptation
Adaptation can be classified under following four heads:
  1. Structeral Adaptation
  2. Physiological Adaptation
  3. Protective Adaptation
  4. Animal association Adaptation.