BIOLOGY IMPORTANT DATES
Class 11th and 12th (NEET)
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Class 11 – Biology Chapter-wise Important Dates
1. The Living World
● 1753 – Carolus Linnaeus publishes “Species Plantarum” (Binomial nomenclature
formalized)
● 1969 – R.H. Whittaker proposed Five Kingdom Classification
2. Biological Classification
● 1866 – Ernst Haeckel proposes the Three Kingdom system
● 1977 – Carl Woese proposed the Three Domain system
3. Plant Kingdom
● 1851 – Wilhelm Hofmeister establishes alternation of generations
● ~425 million years ago – First vascular plants (e.g., Cooksonia)
4. Animal Kingdom
● ~600 million years ago – Appearance of multicellular animals (metazoans)
5. Morphology of Flowering Plants
● 17th–18th century – Early plant morphology studies by Nehemiah Grew and
others
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6. Anatomy of Flowering Plants
● 1830s – Robert Brown identifies nucleus
● 1838–39 – Schleiden & Schwann proposed Cell Theory
7. Structural Organisation in Animals
● 1665 – Robert Hooke discovered cells
● 1839 – Purkinje coins the term “protoplasm”
8. Cell – The Unit of Life
● 1831 – Robert Brown discovers the nucleus
● 1931 – First electron microscope
9. Biomolecules
● 1953 – Watson & Crick propose the DNA double helix
● 1926 – Michaelis-Menten kinetics proposed
10. Cell Cycle and Cell Division
● 1882 – Walther Flemming observes mitosis
11. Transport in Plants
● 1894 – Dixon & Joly propose Cohesion-Tension Theory
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12. Mineral Nutrition
● 1860 – Julius von Sachs and Wilhelm Knop develop hydroponics
13. Photosynthesis in Higher Plants
● 1779 – Jan Ingenhousz shows light is essential for photosynthesis
● 1941 – Hill Reaction discovered
14. Respiration in Plants
● 1940 – Krebs Cycle described by Hans Krebs
15. Plant Growth and Development
● 1934 – F.W. Went discovers Auxin (IAA)
● 1963 – Discovery of Cytokinins
16. Digestion and Absorption
● 1824 – William Beaumont studies digestion physiologically
17. Breathing and Exchange of Gases
● 1954 – Discovery of hemoglobin structure by Max Perutz
18. Body Fluids and Circulation
● 1628 – William Harvey discovered circulation of blood
19. Excretory Products and Their Elimination
● 1827 – Discovery of nephrons
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20. Locomotion and Movement
● 1939 – Discovery of actin & myosin in muscles
21. Neural Control and Coordination
● 1873 – Camillo Golgi invents silver stain for neurons
● 1891 – Charles Sherrington coins “synapse”
22. Chemical Coordination and Integration
● 1905 – Bayliss & Starling discover hormones (secretin)
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Class 12 – Biology Chapter-wise Important Dates
1. Reproduction in Organisms
● ~1.2 billion years ago – Sexual reproduction evolves in eukaryotes
2. Sexual Reproduction in Flowering Plants
● 1824 – First observation of double fertilization in angiosperms (Nawaschin)
3. Human Reproduction
● 1677 – Antonie van Leeuwenhoek observes sperm for the first time
4. Reproductive Health
● 1952 – India launches family planning program
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5. Principles of Inheritance and Variation
● 1865 – Gregor Mendel published experiments on pea plants
● 1902 – Sutton and Boveri propose Chromosomal Theory
6. Molecular Basis of Inheritance
● 1952 – Hershey-Chase Experiment proved DNA is genetic material
● 1953 – DNA structure discovered
● 1961 – Nirenberg cracks genetic code
7. Evolution
● 1859 – Charles Darwin publishes “On the Origin of Species”
● 1920s–30s – Modern Synthetic Theory of Evolution
8. Human Health and Disease
● 1796 – Edward Jenner developed first vaccine (smallpox)
● 1983 – Discovery of HIV
9. Strategies for Enhancement in Food Production
● 1966 – Green Revolution in India begins
10. Microbes in Human Welfare
● 1928 – Alexander Fleming discovers Penicillin
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● 1897 – Beijerinck coins the term “virus”
11. Biotechnology – Principles and Processes
● 1972 – Recombinant DNA technology developed by Cohen & Boyer
● 1983 – PCR technique developed by Kary Mullis
12. Biotechnology and Its Applications
● 1997 – First cloned mammal (Dolly the sheep)
● 2002 – Bt cotton commercialized in India
13. Organisms and Populations
● 1838 – Malthusian theory of population
14. Ecosystem
● 1935 – Arthur Tansley introduces term “ecosystem”
15. Biodiversity and Conservation
● 1992 – Earth Summit (Convention on Biological Diversity)
● 2004 – Tiger conservation plan launched in India
16. Environmental Issues
● 1974 – Chipko Movement in India
● 1987 – Montreal Protocol signed to protect ozone layer
