Important Years in NCERT-Biology | Class 12

🧬 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.