Ncert dates
1. Joseph Priestley in 1770 performed a series of experiments that
revealed the essential role of air in the growth of green plants.
2. Priestley discovered oxygen in 1774
3. Nucleus as a cell organelle was first described by Robert Brown
as early as 1831
4. In (1838), Matthias Schleiden, a German botanist, examined a
large number of plants and observed that all plants are composed
of different kinds of cells which form the tissues of the plant
5. Schwann (1839), a British Zoologist, studied different types of
animal cells and reported that cells had a thin outer layer which is
today known as the 'plasma membrane.
6. Rudolf Virchow (1855) first explained that cells divided and new
cells are formed from pre-existing cells (Omnis cellula-e cellula).
7. Gregor Mendel, conducted his experiments seven years (1856-
1863) and proposed the laws of inheritance in living organisms
8. Julius von Sachs (1860), a prominent German botanist,
demonstrated for the first time, that plants could be grown to
maturity in a defined nutrient solution in complete absense of soil.
9. Mendel published his work on inheritance of characters in 1865
but for several reasons, it remained unrecognised till 1900
10. Down's syndrome, described by Langdon Down in 1866
11. DNA as an acidic substance present in nucleus was first
identified by Friedrich Meischer in 1869. named it as "Nuclein
12. Henking (1891) discovered X-chromosome
13. Fossils discovered in Java in 1891 reveled the next stage, i.e.,
Homo erectus about 1.5 mya
14. D.J. Ivanowsky (1892) recognised certain microbes as causal
organism of the mosaic disease of tobacco
15. M.W. Beijerinek (1898) demonstrated that the extract of the
infected plants of tobacco could cause infection in healthy plants
and called the fluid as Contagium vivum fluidum (infectious living
fluid.
16. Camillo Golgi (1898) First observed densely stained reticular
structures near the nucleus These were later named golgi bodies
17. In 1900, three Scientists (de Vries, Correns and von Tshermak)
independently rediscovered Mendel's results on the inheritance of
characters.
18. The first clinical gene therapy was given in 1990 to a 4-year old
girl with adenosine deaminase
19. By 1902, the chromosome movement during meiosis had been
worked out. Walter Sutton and Theodore Boveri, proposed
chromosomal theory of inheritance.
20. When several factors affect many (bio) chemical process
Blackman's (1905) Law of Limited Factors comes into effect
21. In 1928, Fredrick Griffith, in a series of experiments with
Streptococcus pneumoniae, proposed transforming principle in
bacteria
22. W.M. Stanley (1935) showed that viruses could be crystallised
and crystals consist largely of proteins.
23. Fleming, Chain and Florey were awarded Nobel Prize in 1945 for
the discovery of antibiotics
24. Family planning programme were initiated in 1951 and were
periodically assessed over the past decades
25. The unequivocal proof that DNA is the genetic material came
from the experiments of Alfred Hershey and Martha Chase (1952)
26. In 1953, James Watson and Francis Crick, based on the X ray
diffraction data prpoposed Double Helix model for the structure of
DNA
27. Ribosomes are the granular structures first observed under the
electron microscope as dense particles by George Palade (1953).
28. In 1953, S.L. Miller, an American scientist created similar
condition in a laboratory Scale to proved the theory of chemical
evolution
29. G.N. Ramchandran's discovery of the triple helical structure of
collagen published in Nature in 1954
30. In 1958, Matthew Meselson & Franklin Stahl worked on E.coli
proved semiconservative replication of DNA in prokaryotes
31. In 1958, Taylor worked on Vicia faba proved semiconservative
replication of DNA in eukaryotes
32. " Anatomy of Seed Plants" by Katherine Esau was published in
1960.
33. Melvin Calvin: The mapping of the pathway of carbon
assimilation in photosynthesis eamed him Nobel Prize in 1961.
34. In 1963, wheat varieities Sonalika and Kalyan Sona were
introduced all over the wheat growing belt of India.
35. the year 1963, two enzyme responsible for restricting growth of
bacteriophage in Escherichia coli were isolated.
36. The derivatives of IR-8& Taichung native-1 introduced in 1966.
37. Whittaker (1969) suggested the Five Kingdom Classification
38. T.O. Diener (1971) discovered a new infectious agent (viroid)
that was smaller than viruses and caused potato spindle tuber
disease.
39. Government of India legalised MTP in 1971 with some strict
conditions to avoid its misuse.
40. An improved model of the structure of cell membrane was
proposed by Singer and Nicolson (1972) widely accepted as fluid
mosaic model.
41. Stanley Cohen & Herbert Boyer accomplished the construction
of first artificial recobinant DNA in 1972.
42. Government of India has passed the Water (Prevention and
Control of pollution) Act, 1974 to safegaurd our water resources.
43. Chipko Movement of Garhwal Himalayas in 1974.
44. Realising the significance of participation by local communities,
the Government of India in 1980s has introduced the concept of
Joint Forest Management (JFM)
45. AIDS was first reported in 1981.
46. In India, the Air (Prevention and Control of Pollution) Act came
into force in 1981.
47. In 1983, Eli Lilly (An American company) produced first
genetically engineered insulin by recombinant DNA technology.
48. In order to control environmental pollution, the Government of
India has passed the Environment (Protection) Act, 1986 to
protect and improve the quality of our environment (air, water
and soil.
49. Air (Prevention and Control of Pollution) Act was amended in
1987 to include noise as an air pollutant.
50. Montreal Protocol was signed at Montreal (Canada) in 1987
(effective in 1989) to control the emission of ozone depleting
substances.
51. National Forest Policy (1988) of India has recommended 33
percent forest cover for the plains and 67 percent for the hills
52. A very ambitious project of sequencing human genome was
launched in the year 1990.
53. The historic Convention on Biological Diversity(The Earth
Summit) held in Rio de Janeiro in 1992
54. In 1997, the first transgenic.cow Rosie, produced human
protein-enriched milk (2.4 grams per litre).
55. In 1997, an American company got patent rights on Basmati
Rice.
56. 2000, Maize hybrids that had twice the amount of Lysine and
Tryptophan amino acids were developed.
57. a follow-up, the World Summit on Sustainable Development
held in 2002 in Johannesburg, South Africa.
58. All the buses of Delhi were converted to run on CNG by the end
of 2002
