Current Affairs 11th Class

Exceptions are inherent in biology due to evolutionary divergence. Not only living organisms, but viruses and biomolecules also exhibit exceptional forms. A student of biology must be prepared to accept and enjoy this gesture of nature. Some exceptions have been explained logically, while for others, the reasons are yet to be searched out. Following are noteworthy exceptions in zoology, (1) Mammals are usually terrestrial, fossorial or arboreal but bat is only flying and whale and seals are aquatic mammals. (2) Mature mammalian RBCs are devoid of nucleus except camel. (3) The aquatic larval stage of some salamanders like Ambystoma is able to reproduce (paedogenesis) and attain sexual maturity. It is called neoteny. Total neoteny is found in Necturus, Siren and Proteus. (4) Heart is three chambered in reptiles but four chambered in crocodiles. It is two chambered in fishes but three chambered in lung fishes like Protopterus which possess lung-like structure beside gills. (5) DNA is double stranded in all cells and DNA viruses but single stranded in the bacteriophage \[\varphi \times 174\] and M-13. Likewise RNA is single stranded in all the cells and RNA viruses but double stranded in reovirus, rice dwarf virus and wound tumour virus.

Some interrelated disciplines of biology (career options in biology) from which any field can be selected for further rewarding career. (1) Virology : It is the study of viruses. (2) Agronomy : This branch deals with the management of farms and is the science of crop production. (3) Pathology : It is the study of diseases (their nature, causes, symptoms, effects and control). (4) Breeding : This branch is concerned with the production of new improved races by mating selected parents. (5) Entomology : It is the study of structure, habits and classification of insects. (6) Anthropology : It is the study of physical, cultural, mental and social nature of primitive and modern man. (7) Veterinary science : It deals with the study of domestic animals. (8) Ichthyology or Fishery or Pisciculture : It deals with the study of rearing fish. (9) Apiculture : It deals with the study of bee-keeping for obtaining honey and wax. (10) Poultry : It is the branch of science dealing with the study of raising domestic fowls as chicken, ducks and geese. (11) Food technology : It is the study of processing and preservation of foods, vegetables, fruits, etc. (12) Nutrition : It supplies information for proper nourishment of human and other organisms for healthy living. (13) Forestry : It is concerned with protection and development of forests and to explore the outcome and economic potential of forests. (14) Horticulture : It is the study primarily aimed at the improvement of ornamental and fruit yielding plants. (15) Pharmacology : It deals with study of drugs and preparation of medicines. (16) Bacteriology : It aims at the study of bacteria and includes the exploration of useful and harmful effects. (17) Genetics : The branch which is concerned with differences and resemblances among parents and progeny especially those due to heredity or inheritance. (18) Pharmacy : It deals with the preparation and compounding medicines and dispensing them as per doctor's prescription. (19) Soil Science : It aims at the study of soil, its structure, type and dynamics. (20) Dairy technology : It is the study of manufacture of milk products. (21) Microbiology : It is the study of microscopic organisms. (22) Psychology : The branch of science which deals with behaviour and qualities etc. of human mind. (23) Forensic Sciences: It is the application of scientific knowledge to the question of civil and criminal laws e.g., study of finger prints, blood typing, identification of narcotics etc. (24) Medicine: The branch of science responsible for curing diseases with drugs or other curative substances. (25) Surgery: It is a branch of medicine which deals with physical operations to cure injuries and other diseases of body. (26) Biomedical engineering: It deals with the production of spare parts of man such as artificial limbs, implants and heart, lung machine etc. (27) Physiotherapy : It is the branch of science which mainly aims at curing the diseases, defects and body weaknesses by physical remedies as massage and exercise etc. (28) Genetic more...

460-377 Hippocrates : Used the plants in medicine (Father of B.C. medicine). 384-322 Aristotle : Initiated study of biology  (Father of biology). B.C. 370-285 Theophrastus  : Described 480 kinds of plants in 'Historia B.C.       Plantarum' (Father of botany) and writer of 'cause of plants'. 1590      Invention of the first microscope by Jenssen  and Zacharis Jenssen                                      1665      Discovery of the cellular structure (cells) in cork : Robert Hooke described in book 'Micrographia'.    1675      Anatomia Plantarum : Book by Marcello Malpighi. 1683      Initial separation of bacteria : Antony Von Leeuwenhoek (of Holland) 'animalcules' named.              1694      Malpighi illustrated stomata and parenchyma. 1694      Camerarius described sexual reproduction of plants and importance of pollination.                            1727      Stephan Hales discovered idea of manufacture of food by green plants in sunlight. Father of plant physiology. 1753      Species Plantarum and Genera Plantarum books (Linnaeus) Carl Van Linnae. Systema Naturae, Binomial nomenclature, father of taxonomy. 1759      C.F. Wolff established embryology, gave 'epigenesis' concept. 1761      Discovery of the sexuality of plants : Joseph Gottleib Koelreuter. 1779      Discovery of photosynthesis : Jan Ingenhousz. 1783      First studies of the biology of flowers : Christian Konard Sprengel. 1790      Metamorphosender pflanzen concept of plant metamorphosis : Johann Wolfgang Von Goethe. 1802      Lamarck and Treviranus proposed the term 'Biology'. 1804      Researches chimiques surla vegetation, discovery of the gaseous exchange of plants : Nicolas Theodore de Saussure. 1809      J.B. Lamarck. Theory of inheritance of acquired characters 'philosophie zoolozique' book, use and disuse concept. 1809      Charles Darwin (England) voyage on 'Beagle' ship, 'origin of species' (1859) book. Theory of natural selection and survival of fittest influenced by Malthus. 1817      P. Caventon, discovery and naming of chlorophyll. 1824      Discovery of endosmosis by H.J. Dutrochet, also suggested that all plants and animals are made of cells. 1828      Brownian movement : Robert Brown. 1830      J.E. Purkinje studied movements and pollination. 1831      'Nucleus' in plant cells : Robert Brown 1835      Nucleolus named by Bowman (1840) and first seen by Fontana (1781) but described by Schleiden M.J. (1835) 1835      Named Sarcode for cell fluid : Dujardin M. J. 1837      Named protoplasm : Purkinje J. E. 1838      T.R. Malthus : Suggested that human population increases much faster than food production.          1839      G.J. Mulder : Named proteins. 1839      Cell theory by German Scientists M.J. Schleiden  (Botanist) and T. Schwann (Zoologist). 1840      Study of cell division : Hofmeister. 1840      Mineral nutrition of plants, established overthrow of the humus theory : Justus Von Liebig. 1842      R. Mayer : Light energy changed to chemical energy in photosynthesis. 1844      Properties of protoplasm : Hugo Von Mohl. 1845      Law of conservation of energy : Julius Robert Von Mayer. 1846      Plant cells arise from pre-existing cells : K. Nageli. 1851      Discovery of the homologies in plant reproduction : Wilheim Hofmeister. 1854      Thuret observed sexual union in algae Fucus. 1857      George Bentham and Joseph Dalton Hooker published 'Genera Plantarum''. 1858 , 'Omnis cellula more...

Father of Zoology and Biology and Founder of Embryology  :  Aristotle Father of Botany : Theophrastus Father of Genetics : G.J. Mendel Father of Evolutionary ideas  : Empedocles Father of Eugenics : Francis Galton Father of Mutation : Hugo de Vries Father of Modern Embryology : Karl Ernst Von Baer Father of Palaeontology : Leonardo da vinci Father of Taxonomy : Carolus Linnaeus Father of Special Creation Theory : Father Saurez Father of  Blood groups : K.Landsteiner Father of Blood circulation  : William Harvey Father of Comparative Anatomy : G. Cuvier Father of Modern Genetics  : T. H. Morgan Father of Medicine : Hippocrates Father of Microbiology : Louis Pasteur Father of Immunology : Edward Jenner

Two Ashwini Kumars has been said to be practising medicine during Vedic times. Dhanwantri has been called as 'God of medicine'. Susruta has been called as 'Father of surgery'. Few important references are, (1) Susruta studied human anatomy on dead bodies. (2) Susruta carried plastic surgery on human nose (rhinoplasty). (3) Ophthalmic surgery : Susruta carried an eye surgery like extraction of cataracts. (4) Clotting of blood : Susruta used non-poisonous live leeches for checking clotting of blood in post operative conditions. Now its clearly established that heparin is released along saliva of leeches to produces this kind of effect. (5) Charaka Samhita (100 B.C.) : It is said to be primarily written by Agnivasa under the guidance of Atreya (600 B.C.). Charaka was first to discuss the concepts of digestion, Metabolism and immunity. (6) Taittiriya Upanishad (7–8 B.C.) : In this significant observations have been made about the process of evolution. According to this life originated in space. (7) Manu Samhita or Manu Smriti (200 A.D.) : In this significant Sanskrit literature, evolution has been widely discussed.   Differences between Plants and Animals

Characters	Plants	Animals
Photosynthesis	Show photosynthesis.	Do not show photosynthesis.
Chlorophyll	Contain chlorophyll.	Lack chlorophyll.
Dependence	Dependent upon inorganic substances like \[C{{O}_{2}}\] and \[{{H}_{2}}O\].	Feed on complex organic compounds.
Movement	Are fixed organisms but show bending, twisting etc.	They are capable of moving the whole body.
Branching	Have branched body.	Have compact body.
Sensitivity	Are comparatively less  sensitive and respond slowly.	Are more sensitive and respond quickly.
Cell wall	Cellulose cell wall usually present.	Bear no cellulose cell walls.

A scientist link patterns or draws relationship among a number of isolated facts. Scientist is responsible for determining the principles from the observations on specific cases and finally discovers general principles. Scientists adopt scientific methods based on the following pattern -    

(1) Amniocentesis : However, these days, the amniocentesis is being misused also. Mothers even get their normal foetus aborted if it is a female. This is just equivalent to killing of a normal child. So Govt. of India enforced the Pre-natal Diagnostic Techniques (Regulation and Prevention of Misuse) Act, 1994 since January 1, 1994 under which all genetic counselling centres and laboratories are required to apply for registration. So this technique has been banned in some states like Maharashtra and is under consideration in other states. (2) Bioterrorism : Now a days bio-techniques are being widely used for preparation of bioweapons like antibiotic resistant  micro-organisms. Spores of Bacillus anthracis (cause of anthrax) are produced in biology research labs and stored for decades. Their release may cause anthrax and become the cause of bioterrorism. Such release of antibiotic resistant strains cause communicable diseases like anthrax and plague on endemic or epidemic scale.

Scientific investigations may be basic or applied. Inventions of new technology extend new hopes and open avenues for the work and research which was not possible earlier. Discovery of radioactive isotopes enabled tracing metabolic pathways, development of microscope and then electron microscope provided useful tools to study biology. X-ray crystallography helped in the study of the structure of DNA, protein and many other biomolecules. Biotechnology and genetic engineering are fruitful due to accumulation of knowledge from different sources. It is note worthy that while information gathered from basic researches enriched the field of applied researches, the fruits of applied researches contribute to explore and widen the area of basic researches.

Biology creates an awareness of vast array of forms of life which normally goes unseen. Biology offers a large scope and provides a large field for study. (1) Helps us to understand ourselves better : It unfolds different queries of life alongwith its cultural, social, philosophical and economical aspects. So it helps in understanding the life better. (2) Biology and inter-relationship of living beings : Study of biology helps us in understanding the wonderful phenomenon and laws of nature which finally tell us to predict the behaviour of different living beings under changed conditions. (3) Biology and resources : Biology helps us to know how to tap and conserve the resources available to us e.g. fishes, birds, forests etc. (4) Biology and literature : Knowledge of Natural Biology has greatly enriched the literature with their references in stories and poems etc. Poets and other authors have been inspired by the beautiful and interesting plants and animals and frequently figure them in stories, poems and dramas. (5) Study of nature is a rewarding experience : Many plants like Narcissus, Dahlia, Gloriosa, Roses, Marigold, Aster, etc. are used for ornamental purposes. The variety available in animals is widely enjoyed in zoological parks. Students enjoy excursions to remote places watching never seen before plants and animals. (6) Solving problems : Biology makes us to understand the present day problems such as population growth, pollution, conservation of wildlife and survival of man etc. The future directions of biotechnology, conservation of biodiversity, maintenance of environment  and human welfare remain in the hands of biologists. (7) Biology-Medicinal aspect : Several plants like Atropa belladona, Cinchona are sources of atropine, quinine etc. Many members of fungi such as Penicillium and Streptomyces give rise to antibiotics like penicillin and streptomycin. Plants are the major source of vitamins. Drugs are first tested on animals before being used for treating man. Animals provide scientific hints for the production and use of medicines. Animals are widely used for scientific research and results thus obtained are finally applied to man. The study of animal play an important role in health, nutrition and control of pests. Many diseases like malaria are caused and transmitted by animals. (8) Solving approach of biology : Knowledge for eradication of diseases like malaria, small pox, etc. have been achieved by scientists basically due to desire and determination to solve the problem. (9) Ecosystem and living organisms : Biology helps us in understanding the various ecosystems. The living community and non-living environment interact with each other and exchange of material in them takes place. (10) Biotechnology : Biotechnologists have produced many genetically modified (GM) crops. Plenty of studies are being made by geneticists, evolutionists and cytologists to fudge the efficacy of biotechnology.

(1) Serendipity is associated with scientific method and it refers to discoveries made unexpectedly or by chance. (2) The term 'serendipity' was coined to Horace Walpole in 1754 from the title of the fairy-tale. 'The Three Princes of Serendip (a former name for Sri Lanka)', whose heroes were always making discoveries by accidents and sagacity. (3) Louis Pasteur said that "chance favours the trained mind". because an inquisitive, enthusiastic and intuitive mind may perceive the desired direction for a discovery. (4) In 1922 while Alexander Fleming, the British bacteriologist has a cold, allowed few drops of his nasal mucus to fall on a bacterial culture. (5) Fleming was excited to find sometime later that the mucus could dissolve away the bacteria and the enzyme lysozyme which dissolves bacterial cells could be discovered. (6) One of the best known antibiotics, penicillin, was discovered by Fleming in 1928 as a result of a happy accident. (7) Fleming had been working on Staphylococcus and it happened that some spores of a mould floated into his laboratory through an open window and landed on one of his Staphylococcus colonies. (8) To Fleming's surprise the bacteria were quickly destroyed. (9) The mould was subsequently identified as Penicillium notatum; for this reason the active substance killing the bacteria was called penicillin. (10) Edward Jenner, an English physician, could develop smallpox vaccine by observing that the dairymaids infected with milder cowpox are safer from infection of smallpox. (11) In 1796, Jenner inoculated an 8-year old boy with fluid from cowpox blisters on the hand of a dairymaid, Sarah Nelms. (12) To Jenner's surprise, the boy had become immune to smallpox and this technique of inducing immunity became known as vaccination (Latin 'vacca' means cow)