Planet earth is made up of abiotic and biotic components. The biotic components are obviously the living beings present around us. The question is why do we call them living and how do they differ from non-living?
1.1 Basic principles of life :
A. The living being once produced / born has to survive. For survival, it needs energy and many chemical molecules. For energy, it has to perform metabolism. Metabolism is breaking of molecules (catabolism) and making of new molecules (anabolism).
. From birth onwards, organisms show tendency of growth and development. This growth is a well-orchestrated process. You might have observed sand mounds, boulders grow, etc.This growth is not from within and hence these are not living beings.
C. Growth and development are not the processes which have unlimited time span. At certain point of time, the molecules, organs, systems begin to loose their effective working and become old. This is ageing process of the body.
D. Life has to continue hence the organism tries to produce a young one like itself. It is possible due to reproduction (asexual or sexual). This ensures continuity of race. Mules, sterile worker bees do not reproduce; yet are living. Can we call reproduction as inclusive characteristic of life?
E. As the body looses it's capacity to perform metabolism, the organism dies. F. Any living being responds to thermal, chemical or biological changes in the surrounding. This is unique property of living beings.
There is immense diversity in living organisms. Since time immemorial, variety of organisms are living together on earth. In order to understand the interrelations between living and non-living as well as between two living beings or groups, systematic study of these is essential. This data is also important for various industries and agriculture. Intensive laboratory and field studies in order to identify and classify the organisms form strong basis for meaningful use of the collected data. If we need to study this diversity, certain aids called taxonomical aids can be used. These includes herbaria, botanical gardens, museums, biodiversity parks, etc.
1.2 Herbarium :
The word herbarium (plural-herbaria) was coined by Pitton de Tournefort in the book ‘Elemens’. The art of herbarium was initiated by an Italian taxonomist Luca Ghini (1490-1556). Herbaria are effective tools in taxonomic studies. A herbarium is essentially a dried plant specimen that is pressed, treated and mounted on standard size sheet in order to preserve it.
Date, place of collection along with detailed classification and highlighting with its ecological peculiarities, characters of the plant are recorded on the same sheet. Local names and name of the collector may be added. This information is given at lower right corner of sheet and is called 'label'.
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| Fig. 1.1 Herbarium |
1.3 Botanical Gardens :
Botanical gardens are the places where plants of different varieties collected from different parts of the world, are grown in a scientific and systematic in a in vivo manner. Plants are labeled. The label-board shows scientific as well as common name of the plant.
1.4 Museum :
Museums are the places where, collections of preserved plant and animal specimens are kept. Plant and animal specimens may be preserved in formalin (10% to 40% formaledehyde) in transperent jars. Jars are labelled. Larger animals like birds and mammals are usually stuffed and preserved. This science is known as taxidermy. Specimens in dried form are also kept in museum.
We can even find systematic collections of shells, skeletons of animals, insect boxes in museums.
Thus, biological museums in educational institutes are reference hubs of biodiversity studies.
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| Fig. 1.3 Biological Museum |
1.5 Zoological Parks :
Zoological Park generally known as zoo, is a place of interest for common man. In a zoo, wild animals are kept in captivity. They are protected and care is taken to provide conditions similar to their natural habitat. (ex-situ) In a zoo, a naturalist can study food habits and behavior of animals.
Flora, manuals, Monographs and Catalogue are some other tools of maintaining biodiversity records. Flora is the plant life occurring in a particular area on time. A Monograph describes any one selected biological group where as manual provides information, keys about identification of species found in a particular area.
1.6 Biodiversity parks :
It is an ecological assemblage of species that form self-sustaining communities on degraded / barren landscape e.g. Late Uttamrao Patil biodiversity park Gureghar, Mahabaleshwar. This park is the best model for conservation of natural heritage in urban landscape.
Systematic classification of living organisms is helpful in understanding the interrelations. In order to understand interrelations between organisms and maintain harmony on planet earth, study of biodiversity is a must.
1.7 Key :
Key is taxonomical aid used for classification of plants and animals. The keys are based on contrasting characters. One of the contrasting characters gets accepted and other rejected. The statement in key is called a lead. Normally keys are analytical in nature. Let us study about classification of living organisms in next chapter.
