We all know about the living world ; that what is living world and what are characteristics of living organism. Now did you all know that In the living world there are varieties of organism which is called as the diversity in the living world. In this article, we will know about the Biodiversity or well known The diversity in living world.
The term Biological Diversity or biodiversity (termed by W.G. Rosen) refers to the variety of life forms and habitats found in a defined area.
UNEP (1992) defines it "as the variety and variability of all animals, plants and micro-organisms and the ecological complexes of which they are a part."
Biodiversity represents the totality of genes, species and ecosystem of a region. It includes diversity within species or between species and of eco-systems. The earth's biological resources are vital to humanity's economic and social development.
Globally, so far 1.75 million species have been identified against the estimates ranging from 3 to 100 million. There is growing recognition that biodiversity is a global asset of tremendous values to present and future generations. At the same time, the threat to species and ecosystems has never been as great as it is today, as a result of which species extinction caused by human activities continues at an alarming rate. This calls for global and national actions towards conservation of biodiversity.
Concept of hot spots of biodiversity was developed by Norman Myers in 1988. He identified 25 hot spot area worldwide. Out of 25 hot spot areas two (Eastern Himalayan and Western Ghats) are found in India.
The visible organism inhabitating our earth are mainly of two types –
1. The Plants
2. The Animals.
The all universal concept of Biology (of living organism) apply equally to both animals and plant, yet these two differ at some characteristics, which are as follows:
Difference B/w Animals and Plants
1. Cellular structure: Although basically similar, plant and animal cells differ in characteristic enumerated in following chart :
Plant Cell Animal cell
Cell wall present viz. Cell wall absent.
made up of cellulose.
Chloroplast present Chloroplast absent.
which has Chlorophyll.
Vacuoles present. Vacuole absent.
Lack centriole. Possesses centrioles
2. Growth: Some embryonic reserve tissues persist throughout life in the plants. That is why, plants continue growing and forming new parts throughout life and become branched. In animals, embryonic tissues are used up early. Hence, new organs cease to form after embryonic development and the body typically has a fixed shape. Even the growth of body continues only upto a certain age, and the power of regeneration of lost or damaged parts is very poor in comparison to the plants.
3. Locomotion and Movement: Most animals can move about from place to place (locomotion) and can also move parts of their bodies. Excepting a few lower forms, plants are usually fixed in the ground by means of roots and, hence, immobile. Some spontaneous movement is, however. exhibited by some of their parts, such as the leaves and flowers.
4. Body Organization:
As compared to the animals, plants have a simpler body organization, with a fewer types of organs such a s roots, stems, leaves and flowers.
5. Nutrition: The most important difference between plants and animals concerns their nutrition. Carbohydrates, lipids and proteins are the major nutrients (macronutrients) for all organisms. triente Plants synthesize these organic nutrients from their inorganic constituents obtained from the environment. This is called photosynthesis, because it occurs in presence of sunlight with the help of chlorophyll.
Animals have no chlorophyll and, hence, cannot synthesize the nutrients. Obviously, the nutrients synthesized by plants nourish both plants and animals.
The nutrition of plants is thus autotrophic (holophytic), while that of animals is heterotrophic (holozoic).
6. Trapping of solar energy: Sunlight is the only source of energy required for synthesis of organic nutrients on present earth. This solar energy is a kinetic energy. Only green plants can trap it in C-C or C-H bonds with the help of chlorophyll in photosynthesis, synthesizing carbohydrates and then, the other macronutrients from carbohydrates.
7. Irritability: Plants have poorer responsiveness to environmental changes. Hence, their responses are extremely slow, minimal and indistinct. Responsiveness in animals is well-developed due to evolution of sensory structures and nervous system.
8. Storage of carbohydrates: Animals store carbohydrates in the form of glycogen, while plants store these as starch.
9.Absorption of minerals: Plants absorb minerals from the soil in water-soluble forms and utilize the same for their metabolism, whereas animals take their food in solid form.
10. Special excretory system: Animals have special excretory system to get rid of their waste products, whereas in plants excretion is done through removal of bark and fall of senescent leaves.
11. Centrosome (= Central body): In animals a star shaped structure called centrosome is Present near the nucleus of the cell and this plays a significant role in cell division. This is absent in most plants. However this is found in some lower plants e.g., some of the Algae, Fungi.
12. Lysosome: A special type of body called lysosome containing large number of hydrolyzing enzymes is present in animal cells only while in plant cells examples of their presence are few.
13. Vacuoles: A fully developed plant cell usually has a large central vacuole but it is not found in animal cell.
14. Cytokinesis: In animal cells, separation of daughter cells takes place by an equatorial constriction (i.e., periphery to centre) while in plant cells cytokinesis starts with the formation of phragmoplast which comprises the accumulation of interzonal microtubules and golgi vesicles first in the centre and then migrating towards the side walls (i.e., from centre to periphery).
This structure is transformed into cell plate which separates the territories of the daughter cells; within cell plate the primary wall is produced later.
Study of Plants and animals:
Thus, Biology which is regarded as Study of life is divided into 2 main Branches:
One is the study of plants and the other is study of animals.
The study of plants is called as Botany and Theoprastus is known as the Father of Botany.
The study of animals is known as Zoology and Aristotle is known as Father of Zoology.
India: A Treasure of Biodiversity
India is known for its rich heritage of biodiversity. In biological diversity parlance, India is one of the 17 mega-diverse countries in the world. With only 2.4% of the world's area, India accounts for 7-8% of the world's recorded plant (about 47,000, of which approximately 15,000 are of known medicinal value) and animal species (about 91.000).
India's ten biogeographic zones possess an exemplary diversity of ecological habitats like alpine forests, grasslands, wetlands, coastal and marine ecosystems and desert ecosystems. India has four out of thirty four global biodiversity hotspots, which is an indicator of high degree of endemism (of species) in India. About 5.150 plant species and 1,837 animal species are endemic to India.
India's biodiversity includes wild relatives of agricultural crops and domesticated animals. India has 16 major types and 251 subtypes of forests. The large mosaic of distinct agro-ecosystems has contributed to diverse cropping pattern and systems across the country. Western ghat of India is one of the well known hotspots of biodiversity. Biodiversity Act of India was passed by Parliament in the year 2002.
Now after getting the knowledge of biodiversity ; plants and animals and their studies let us go to the new unit that is the Biological Classification. After knowing about plant and animal now we should know how were they identified, named and on what basis these organisms were divided into many different categories. We will continue all this in the new article and the new label named as Biological Classification.
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