Sciencegajab

 BIOLOGICAL CLASSIFICATION 1. ARISTOTLE : o First scientific approach to classify the organisms o Used simple morphological characters o Classify the plant into herb, shrub & tree. o Classified animals on the basis of presence / absence of Red blood   2. LINNEAUS : o TWO KINGDOM CLASSIFICATION --> PLANTAE and ANIMALIA . o This system did not clear the position of unicellular/multicellular, prokaryotic/eukaryotic organisms.     3. R. H. WHITTAKER: o Five kingdom classification in 1969 ( , ) o Basis of 5 Kingdom --> Five Criteria • Cell structure, • Thallus organisation, • Mode of nutrition, • Reproduction and • Phylogenetic relationships.   o The five kingdoms are : ● Monera ● Protista ● Fungi ● Plantae ● Animalia . 4. MONERA : o Prokaryotic, o Cellular body organisation, o Non- cellulosic cell wall ( ) o Mode of nutrition is autotrophic and heterotrophic. @Highest diversity o Cell wall is made up of polysaccharides and amino

 MINERAL NUTRITION 1. IN 1860, JULIUS VON SACHS (GERMAN BOTANIST) --> Demonstrated, for the first time, that plants could be grown to maturity in a defined nutrient solution in complete absence of soil. 2. THIS TECHNIQUE OF GROWING PLANTS IN A NUTRIENT SOLUTION IS KNOWN AS HYDROPONICS.   3. Through hydroponics technique, impact of a specific minerals can be studied by adding/substituting or removing that mineral. 4. By this method, essential elements were identified and their deficiency symptoms discovered. 5. Hydroponics technique has been successfully used in commercial production of vegetables such as tomato, seedless cucumber and lettuce. ESSENTIAL MINERAL ELEMENTS 6. Plants obtain their inorganic nutrients from air, water and soil. Plants absorb a wide variety of mineral elements. 7. Not all the mineral elements that they absorb are required by plants. 8. Out of the more than 105 elements discovered so far, less than 21 are essential and beneficial for normal pl

 PRINCIPLES OF INHERITANCE AND VARIATION 1. GENETICS is study of  Inheritance & Variations in organism. 2. HERIDITY   Transfer of information from one generation to next 3. Father of genetics  G.J. MENDEL 4. Father of Cytogenetics is Morgan 5. Physical basis of heredity is GAMETES (It’s Mendel’s finding) 6. Chemical basis of HERIDITY GENES 7. Vehicle of heredity Chromosomes 8. Biochemical nature of genes  DNA (Proved by Avery et all in 1944) 9. Mendel published his findings on garden pea plant in “Annual proceedings of the natural history society” of Brunn in 1866. 10. Gregor Johann Mendel, conducted hybridisation experiments on Garden peas for seven years (1856-1863) and proposed the laws of inheritance in living organisms. 11. Rediscovery of Mendel work           ➤By CORRENS,TSCHERMARK & DE VRIES in1900. 12. IMPORTANT TERMINOLOGY : o Character term is used for a heritable feature o Trait term is used for variants of character o GENE  ➤JOHANSSEN used this term for Mendel’s