Modern Biology
Increasing advancement in biotechnology has brought about a veritable explosion of Biological knowledge since early 1950s.This vast modern biological information has uncovered intimate details of Nature in respect of unity continuity and diversity of the Living world it has generated certain new biological concepts which are universally applicable to all organisms, binding these into a single heritage. These modern Unifying concepts of Virology are as follows:
1. Concept of Organization: .According to this concept, all activities connected with life is based upon chemical and physical principles. Thus it implies that life resides not in the constituent atoms and molecules of protoplasm, but in its chemical organization. Hence when scientists have fully understood the physic chemical organization. of protoplasm they create live in the laboratory.
2. Concept of Biogenesis: Scientists agree that the living matter protoplasm originated by gradual chemical evolution in the organization of nonliving matter ,but suitable environmental conditions necessary for such an evolution are not found upon present earth these existed upon primitive earth billions of years ago. Hence new organisms conform upon the present earth only from pre existing ones Omnis vivo ex vivo
3. Cell Theory: According to this theory, all organisms are formed of one or more structural and functional init masses of protoplasm called cells, and of cell products. Like organisms, new cells can form only from pre existing cells similar in structure, chemical organization and metabolism. The life of organisms is the sum tidal of the metabolism. The life of am organism is the sum total of the metabolism of its body cells.
4. Organic Evolution: This is the greatest unifying concept of Modern Biology .It holds that none of the more than 15lacs of known diverse types species of organisms, existing upon present earth, has originated independently by itself. All types have arisen from comparatively simpler and common ancestors in there mote past by accumulation of modifications through innumerable generations.
5. Gene Theory: All organisms possess ultramicroscopic particulate structures, called genes, which carry coded information's of characteristics from one to the next generation, thus acting as units of heredity or inheritance. Varied recombination of genes in members of future generations and chemical changed in the genes help evolution of newer species from older ones.
6. Enzyme Theory: Thousands of chemical reactions occur very moment in each living cell under metabolism for them maintenance of its life. Normally, each reaction is catalyzed by an organic catalyst called enzyme
7. Genie control of Characteristics Biochemical Genetics: Metabolic enzymes all proteins as well as the other proteins which are the main components of cell architecture, are synthesized in accordance with the coded dictates of genes. That is why, all structural and functional characteristics of a cell are gene controlled through synthesis of specific proteins. Thus this is the mechanism how genes transmit characteristics from one to the next generation .Accordingly George Beadle and Edward Tatum 1941 hypothesized one gene one specific protein one structural or functional hereditary characteristic:
8. Variable or Differential Gene Activity: All body cells of a multicellular organism arise by repeated mitotic divisions from, a single zygote cell. Hence all possess the same complement of genes .How then there is a division of labour amongst these cells how they distinguish structurally and functionally into varied types of cells of multicellular body .Modern scientists have discovered that in each particular type of cells of a multicellular body, only a specific part of the genotype is active; the rest is rendered inactive with the help of his tone proteins found in the chromosomes. Thus variable portions of the same genotype are functional in different cell types
9. Organism, its Environment and Homeostasis: Since every organism has to vary regular chemical exchange with its immediate environment. it has to regularly react to the ever changing environmental conditions for maintaining the harmony functions of maintaining the constancy of internal environment was discovered by Claude Bernard 1860 and named homeostasis by Walter B. Cannon 1932.