🌟 Important Points of NCERT 🌟

1. 1770 : Joseph Priestley - Essential role of air in growth of green plant.
2. 1774 : Joseph Priestley - Discovered O2.

3. 1831 : Robert Brown - Ist discovered and described nucleus.

4. 1838 : Schleiden (German Botanist) - Work on plants.
5. 1839 : Schwann(British Zoologist) - Work on both plants & animals.

6. 1855 : Rudolf Virchow - Omnis cellula-e-cellula (cells arises from
pre-existing cells).

7. Life originate from pre-existing life : Pasteur (Yeast).

8. Life originate from non-living (decaying & rotting matter) : Spontaneous
generation.

9. Life originate from pre-existing non-living organic molecules (RNA,
Protein)- Oparin (Russia) & Haldane (England)- Chemical Evolution.

10. 1856 - 1863 : Mendal experiment on garden pea. (7 years)
11. 1860 : Julius von Sachs - Developed hydroponics.

12. 1865 : Mendal published his work.

13. 1866 : Langdon Down - Down’s syndrome.

14. 1869 : Friedrich Meischer - Ist identified DNA and named it nuclein.

15. 1891 : Henking - Discovered X-body.

16. 1891 : Fossil discovered in Java - Homo erectus.

17. 1892 : Ivanowsky - Discovered virus.

18. 1898 : Beijerinek - Contagium vivum fluidum (infectious living fluid).

19. 1898 : Camillo Golgi - Discovered (observed) G.B.

20. 1900 : de Vries, Corre ns and von Tsche rmak inde pende ntly
rediscovered Mendel’s results.

21. 1902 : Chromosome movement during meiosis has been worked out.

22. 1905 : Law of limiting factor (Blackmann).

23. 1928 : Fredrick Griffith - Transforming experiment with Streptococcus
pneumoniae (Diplococcus).

24. 1935 : Stanley - Crystallised viruses.

25. 1937 : Ramde o Misra obtained Ph.D. in Ecology from Lee ds
university (U.K.).

26. 1938 : Coelocanth fish caught in South Africa.

27. 1945 : Fleming, Chain & Florey - Awarded Nobel prize.

28. 1950 : Watson obtained Ph.D. on a study of the effect of hard X-rays
on bacteriophage multiplication.

29. 1951 : Family planning programme started in India.

30. 1952 : Hershey & Chase-experiment on bacteriophage or Bacterial virus
gives unequivocal proof that DNA is the genetic material.

31. 1953 : Miller experiment - Methane, ammonia, hydrogen & water
vapour.

32. 1953 : Watson & Crick - Double helical structure of B-DNA &
replication scheme.

33. 1953 : Palade : Discovered ribosome.

34. 1954 : Ramachandran - Triple helical model of collagen, published
in Nature.

35. 1954 : Crick complete d Ph.D. on a thesis “X-rays diffraction :
polypeptides and proteins.

36. 1958 : Meselson & Stahl - Work on E.coli proves semiconservative
replication of DNA in prokaryotes.

37. 1958 : Taylor - Work on Vicia faba proves semiconservative replication
of DNA in eukaryotes.

38. 1960 : Katherine Esau - Published “Anatomy of Seed Plants.”

39. 1961 : Melvin Calvin - Nobel Prize.

40. 1962 : Watson, Crick and Wilikins - Nobel Prize.

41. 1963 : Wheat varieties (Sonalika & Kalyan sona) introduced.

42. 1963 : Two enzyme responsible for restricting growth of bacteriophage
in E.coli were isolated.

43. 1966 : Derivative of IR-8 & Taichung native-I introduced.

44. 1969 : Whittaker - Five kingdom classification.

45. 1971 : Govt. of India legalized MTP.

46. 1971 : Diener- Discovered Viroid(free RNA without capsid).

47. 1972 : Singer & Nicolson - Fluid mosaic model.

48. 1972 : Stanley Cohen & Herbert Boyer - Formed Ist recombinant DNA.

49. 1972 : Establishme nt of NCEPC - National Committe e for
Environmental Planning & Coordination.

50. 1974 : Water act.

51. 1980 : Joint forest management, (JFM).

52. 1981 : AIDS was Ist reported.

53. 1981 : Air act.

54. 1983 : Eli Lily (An American company) produces insulin in E.coli by
recombinant DNA technology.

55. 1984 : Establishment of MOEF : Ministry of Environment & Forest.

56. 1986 : Environment Protection Act.

57. 1987 : Montreal protocol. Held in Montreal, Canada.

💐 Share & React ❤️ below.

✅ Concave Mirrors:
By reflection of light, concave mirrors give real, inverted images if the object is beyond the focus and a virtual, erect, enlarged image if the object has a distance less than the focal length from the pole of the mirror.

👉🏻 Uses of Concave Mirrors:
➖ Concave mirrors are used in torches, searchlights, and headlights of vehicles to get powerful parallel beams of light.
➖ Concave mirrors are also used as shaving mirrors to see a larger image of the face.
➖ Dentists use concave mirrors to see bigger images of the teeth of the patients.
➖ Large concave mirrors are used to focus sunlight to produce heat in the solar furnaces.


✅ Convex Mirrors:
By the reflection of light convex Mirrors always give a virtual, erect, diminished image of the object kept infront of the mirror.

👉🏻 Uses of Convex Mirrors:
➖ The convex mirror is used as a side-view mirror in vehicles to give a smaller view of the vehicles coming from behind.
➖ They are used in shops and supermarkets and any other place where there is a requirement for detecting burglars.
➖ Convex mirrors are used in making lenses for sunglasses.
➖ Convex mirrors are used in magnifying glasses, and telescopes.
➖ Convex mirrors are used to reflect street light; because they can reflect over a wide area.
➖ Convex mirrors are kept at the street corners to avoid collisions.

today's quiz is from Inorganic chemistry >> Classification of elements and periodicity in properties >> Atomic radius