🧬 Important Years from NCERT Class 12 Biology
📘 Chapter 4 – Reproductive Health
| Year | Event |
|---|---|
| 1951 | Introduction of Family Planning Programme by Government of India. |
| 1971 | Government of India legalised Medical Termination of Pregnancy (MTP). |
| 2017 | Medical Termination of Pregnancy (Amendment) Act. |
📘 Chapter 5 – Principles of Inheritance and Variation
| Year | Event |
|---|---|
| 1856–1863 | Mendel’s hybridisation experiments on garden peas. |
| 1865 | Mendel published his work. |
| 1866 | Langdon Down first described Down’s Syndrome (Trisomy 21). |
| 1891 | Henking discovered the X-body while studying insects. |
| 1900 | Mendel's work rediscovered by de Vries, Correns, and von Tschermak. |
| 1902 | Chromosomal movement during meiosis was understood. |
📘 Chapter 6 – Molecular Basis of Inheritance
| Year | Event |
|---|---|
| 1869 | DNA identified as 'nuclein' by Friedrich Miescher. |
| 1928 | Griffith's experiment on the Transforming Principle. |
| 1933–1944 | Avery, MacLeod, and McCarty's biochemical characterisation of the Transforming Principle. |
| 1952 | Hershey and Chase proved DNA is the genetic material. |
| 1953 | Watson and Crick proposed the double helix model & semiconservative replication model. |
| 1958 | Meselson and Stahl's experiment proved semiconservative DNA replication. |
| 1958 | Taylor's experiment on Vicia faba also supported semiconservative replication. |
| 1990 | Launch of Human Genome Project. |
| 2003 | Completion of the Human Genome Project. |
| 2006 | Sequence of chromosome 1 completed. |
📘 Chapter 7 – Evolution
| Year | Event |
|---|---|
| 1953 | S.L. Miller’s experiment proving chemical evolution. |
📘 Chapter 9 – Strategies for Enhancement in Food Production
| Year | Event |
|---|---|
| 1963 | Introduction of high-yielding wheat varieties – Sonalika and Kalyan Sona. |
📘 Chapter 11 – Biotechnology: Principles and Processes
| Year | Event |
|---|---|
| 1963 | Isolation of Restriction Endonucleases in E. coli. |
| 1972 | First recombinant DNA created by Stanley Cohen and Herbert Boyer. |
📘 Chapter 12 – Biotechnology and Its Applications
| Year | Event |
|---|---|
| 1983 | Genetically engineered insulin developed by Eli Lilly. |
| 1990 | First clinical gene therapy (ADA deficiency in a 4-year-old girl). |
| 1997 | Transgenic cow Rosie produced human protein-enriched milk. |
| 1997 | US company got patent rights on Basmati rice. |
📘 Chapter 15 – Biodiversity and Conservation
| Year | Event |
|---|---|
| 1992 | Earth Summit held in Rio de Janeiro. |
| 2002 | World Summit on Sustainable Development. |
📘 Chapter 16 – Environmental Issues
| Year | Event |
|---|---|
| 1974 | Water (Prevention and Control of Pollution) Act enacted. |
| 1974 | Chipko Movement started in Garhwal Himalayas. |
| 1980 | Joint Forest Management (JFM) introduced in India. |
| 1981 | Air (Prevention and Control of Pollution) Act enacted. |
| 1986 | Environment (Protection) Act enforced. |
| 1987 | Air Act amended to include noise as a pollutant. |
| 1987 | Montreal Protocol signed to control ozone-depleting substances. |
| 1988 | National Forest Policy introduced in India. |

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