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Bio Zoology  Biology  Higher Secondary Second Year  Tamil Nadu State Board Syllabus Human Physiology Content Zoology Introduction – Carbohydrates – Proteins – Lipids – Vitamins – Minerals – Water – Balanced diet – Calorie values (ICMR standards) – Obesity – Hyperglycemia – hypoglycemia – Malnutritions. Digestion : Enzymes and enzyme action – Brief account of following – Dental caries – Root canal therapy – Peptic ulcer – Hernia – Appendicitis – Gall bladder stone – Liver cirrhosis – Hepatitis. Bones and Joints (Major types) : Fractures – Dislocations – Arthritis – Rickets and osteomalacia – Orthopaedics – Gout. Muscles : Muscle action – Muscle tone – Rigor mortis – Muscle pull (hernia) – Isometric and aerobic exercises (Body building) – Myasthenia gravis. Respiration : Process of pulmonary respiration ...

Modern concept of Natural Selection (or) Modern synthetic theory of  Evolution Modern development in biological fields such as Cell biology, Genetics and Populations genetics helped in the development of modern synthetic theory of evolution. It was caused due to contributions made by eminent scientists such as Th. Dobzhansky, S.Wright, H.J.Muller, J.S. Huxley, R.A.Fisher, Ernst Mayr, G.L.Stebbins and others. The basic concept of modern synthetic theory was provided by Th. Dobzhansky in his book titled “Genetics and the Origin of species” (1937) G.L.Stebbins in his book “Process of organic evolution” (1971) suggests five basic processes essential for evolution. They are gene mutations, chromosomal aberrations, genetic recombinations, natural selection and reproductive isolation. Contributions made by others provided additional factors such as Hardy-Weinberg equilibrium, Genetic drift and Polymorphism. 1. Gene Mutations Since proteins perform several functions, they determine many of the...

Objections to Darwinism While the ideas of Darwin, related to reproductive capability, prevalence of variations, concept of struggle and survival of suitable forms are all commonly accepted, there are certain drawbacks in his original theory. 1. Darwin could not explain, the origin and cause for variations while insisting their importance in progressive evolution. 2. He overemphasized the importance of the ‘fittest’ organisms. During later periods it has been suggested that ‘fit’ and fitter forms can also exist along with the fittest. 3. As the principle of inheritance as explained in the later years were not available during Darwin’s time. Hence he believed in the theory of ‘pangenesis’. According to this concept from every organ in the body very minute such replicate structures will orginate. Later they are transferred to the gonads for transmission to future generations. 4. ‘Over-specialization’ as in Irish deer and its consequent harmful effect on animals had not been accounted for...

The Theory of Natural Selection During his period of study Darwin has made several observations and collected facts. Through these facts he arrived at certain conclusions. These conclusions constitute Darwinism. Thus Darwinism or the theory of Natural selection includes the following elements. 1. Overproduction or Prodigality of nature All living beings have an innate desire to reproduce and form their own progeny. In this attempt they have the capacity to multiply in a geometrical manner. Such an enormous reproductive potentiality can be observed in all species of organisms. For example a single female salmon fish can produce 28,000,000 eggs in a season. A common oyster of the Atlantic coast may release as many as 80 million eggs in one season. At the time of breeding the ovaries of a cod fish may contain 10 million eggs. (theory of natural selection) If natural processes of reproduction are allowed without any check a single pair of English sparrows can produce 275 billion descendent...

Darwinism Darwinism comprises the natural selection concept as advanced by Charles Robert Darwin in 1859. His theory provided the correct idea to explain all processes and intricate mechanisms of evolution. The theory of natural selection is considered on par with Newton’s law of gravitation and Einstein’s theory of relativity. The monumental work of Darwin was titled as “The Origin of species” (the original full title of the book was ‘On the Origin of species by means of Natural Selection, or the Preservation of favoured Races in the struggle for life’). The book of Darwin convincingly demonstrates the fact of evolution. Further, it elaborates on the theory of natural selection as a convincing mechanism for providing evolutionary transformations. Charles Darwin was born in Shrewsbury, England on February 12, 1809. While studying in college at England through his friendship with Professor J.S. Henslow, Darwin became familiar with Botany. Later he accepted the job of a naturalist aboard...

Neo lamarckism Lamarck’s ‘theory of inhertitance’ was further studied by a group of scientists. Their ideas supporting Lamarck’s opinion collectively constitute neo Lamarckism. The neo Lamarckians were of the opinion that ‘adaptions’ are universal in nature. An adaptation happens through causal relationship of structure, function and environment. Due to changes in the environment, habits and life style of organism gets altered. Thus gradually the organism acquires new structures. The newly obtained character gradually becomes an inheritable trait. This opinion and argument is a modified form of Lamarckism. These ideas stressed direct action of environment on organisms. Support to neo-Lamarckian concept – Experiments (Neo lamarckism) Neo Lamarckism 1. McDougall (1938) tried to prove that learning is an acquired character that can be inherited. He did his experiments on rats. He deviced a ‘T’ shaped tank. The tank had two exits. One exit was well lighted. However at the terminal reg...

Lamarck Evolution Laws Jean Baptiste de Lamarck (1744 – 1829) is well known for his theory of evolution. In 1809 he published his book titled ‘Philosophie Zoologique’. This book contains his views on evolutionary mechanisms. Eventhough the views of Lamarck are not fully accepted, he occupies a very important place in the history of evolutionary thought. The theory of evolution as proposed by Lamarck is popularly known as the ‘theory of inheritance of acquired characters’. According to this theory modifications or changes acquired during the life time of an organism can automatically be transmitted to succeeding generations. While elaborating this theory, Lamarck advanced four laws or propositions. I Law (or) Proposition ‘In evolution, during course of time, organisms or their component parts gradually tend to increase in size. Lamarck cited the evolution of horses as an example to explain this law. The modern horses, namely, Equus evolved from very small ancestral forms called Hyr...

THEORIES OF EVOLUTION Introduction Several opinions had been made available to explain the origin and existence of various forms of life. The existing living beings show characteristic resemblances in form and functions. There are evidences for succession of several types of living organisms occupying earth. Populations of animals and Plants tend to undergo predictable changes in their population intensities. An explanation to all these interesting natural happenings had been attempted through various modern theories of evolution. An initiation for such evolutionary thought process was well provided by Lamarck. This evolutionary theorizing culminates in the modern synthetic theory of evolution afforded by different fields in biology. (THEORIES OF EVOLUTION) Related Topics in Zoology: Bio Zoology All Important Topics Livestock and Management Important cattle breeds and their characteristics Milch breeds (or) Dairy breeds Dual purpose breeds & Draught breeds Exotic breeds of cattle C...

Autoanalyser To assist in the diagnaosis of diseases and disorders and to monitor therapy, a wide range of clinical tests has been developed. The demand for investigations is growing with the growing population and diseases. To get fast results on a large number of specimens, it is becoming inevitable to replace manual methods. This could be done by autoanalysers. With help of autoanalysers an increased work load can be processed rapidly and with reproducible results. To maintain the quailty of results, standards (samples of Known values) will be run along with every batch of test samples. Advantages of an autoanalyser : 1. Accuracy is more when compared with manual method. 2. Large number of samples may be processed in minimal time. 3. Two or more assays may be performed simultaneously. 4. Calculations are not required. Disadvantages of an autoanalyser : 1. It is impractical for small number of specimens. 2. Instruments may fail occasionally. 3. Additional training of the staff about ...

Endoscopy (Laproscopy) techniques Endoscopy is a method of examining the interior of a body cavity or hollow organ (e.g., oesophagus, stomach) using an endoscope, a narrow, flexible fiber optic instrument that conducts light. Until recently, surgery was the most traditional of medical practices, employing techniques and instruments developed more than a century ago, but now patients have a new choice. Endoscopy is a minimally invasive approach to sugery of various parts It accomplishes traditional surgical goals while delivering less pain, faster recovery, and happier patients.The procedure does not require hospital admission and acute care and observation may be performed outside the premises of a hospital. Outpatient procedures performed at hospitals or ambulatory centers allow the patient to go home or return to work within a short period after endoscopic diagnosis. Types of Endoscopy 1. Bronchoscopy: (trachea and lung’s bronchial trees) 2. Colonoscopy: (colon and large intestine) 3...