Genetics and Plant breeding pointers 45

1. Meristem culture is generally used for propagation.

2. Monocyclic and polycyclic tests for disease resistance were suggested by Zodiak.

3. Most restriction endonucleases produce staggered cuts.

4. Most tetraploid and hexaploid wheat carry two dominant genes, Kr1 and Kr2, which prevent seed development in secale.

5. Most tetraploid and hexaploid varieties of wheat having two recessive genes, Kr1 and Kr2, inhibit seed development in crosses with secale.

6. Mostly some clone variants are recovered in R1 generation.

7. New Leaf is a variety of potato resistant to Colorado beetle.

8. Non-biological factors harmful to crops are known as abiotic stresses (e.g., pH, high and low temperature).

9. Oligogenic disease resistance does not show continuous variation.

10. Ono is a variety of somaclone of sugarcane resistant to Fiji disease.

11. Pathogenicity is the ability of the pathogen to cause disease.

12. Pathotypes are identified by using ideal differentials.

13. Particular virus coat protein is inserted in plants to make those plants resistant to that coat protein.

14. Physiologic races are identified using a host tester or differential host.

15. Phytoalexins are antimicrobial/terpenoid chemicals produced by the host in response to infection by a pathogen.

16. Plants developed through gene transfer are called transgenic plants.

17. Plants regenerated from callus/cell culture are known as R0 plants.

18. Plasmid is a self-replicating circular DNA molecule but survives only under specific conditions.

19. Polyethylene glycol (PEG) is the most commonly used fusogen.

20. Polymerase Chain Reaction (PCR) is nicknamed the "people's choice reaction."

21. PCR was discovered by Kary Mullis and Michael Smith and awarded the Nobel Prize in 1993.

22. Pomato variety developed through somatic hybridization between potato and tomato.

23. Priestley gave the concept of boom and bust cycle.

24. Primer is a small oligonucleotide sequence used in PCR for DNA amplification.

25. Probe is a small DNA or RNA sequence used for identification of complementary DNA sequences from DNA samples.

26. In protoplast culture, the cell wall regenerates first.

27. Protoplast means a cell without a cell wall.

28. Pusa Jai Kisan is a variety of mustard developed through somaclone and isolated from Varuna (also known as BIO 902).

29. QTL stands for Quantitative Trait Loci.

30. Rescue is a variety of wheat resistant to insects.

31. Resistance to black leg (Phoma lingam) was transferred into Brassica napus through protoplast fusion with Brassica nigra.

32. Reverse transcriptase enzyme was discovered by Tamin and Baltimore.

33. Reverse transcriptase is an RNA-dependent DNA polymerase used to obtain complementary DNA copies of RNA.

34. Reverse transcriptase is generally obtained from Avian myeloblastosis virus.

35. Rivarin and Cycloheximide are antiviral agents.

36. RNA polymerase is an enzyme responsible for transcription, using DNA as a template for RNA production.

37. Scarlet is a somaclone of sweet potato.

38. Secondary metabolites are chemicals not used by the cell and are not products of primary metabolism.

39. Selection of hybrid cells in protoplast fusion technology is a major limitation.

40. A small piece of tissue used in vitro culture aseptically is known as explant.

41. Somaclonal variation is a heritable variation (quantitative and qualitative) present in vitro.

42. Somatic hybrid denotes a fusion product of two parent cells.

43. Some varieties of host plants used for identification of physiologic races are known as differential host or host tester.

44. Southern leaf blight is caused by Dreschlera maydis, which produces a toxin that binds to mitochondria.

45. Southern leaf blight of corn is associated with T-cytoplasm.

46. Soybean variety Roundup Ready is resistant to glyphosate.

47. Structural genes encode diffusible products.

48. Sucrose is generally used as a carbon source in tissue culture media and is essential for anther culture.

49. Biotechnology is a technique combining tissue culture and molecular biology.

50. Tissue culture temperature may vary from 18-25°C.

51. The term Vertifolia effect was given by Vanderplank.

52. Terminator gene causes seeds produced by a crop to be non-viable.

53. The bar gene, conferring resistance to phosphinothricin, was isolated from Streptomyces sp.

54. The concept of clean crop and dirty crop multiline approach was suggested by Marshall.

55. The concept of strong and weak oligogenes was given by Vanderplank.

56. The first somatic hybrid was produced by Carlson and co-workers.

57. The first transgenic plant resistant to virus was produced in 1986 in tobacco.

58. The larger the size of shoot tip explant, the higher the chance of virus presence in the regenerated plant.

59. Major resistant genes activate other genes to produce a hypersensitive response.

60. The shoot tip (100 to 1000 μm) is usually virus-free and used in meristem culture for virus elimination.

61. The term agroinfection was coined by Grimsley et al. in 1986.

62. Thermotherapy is effective against viruses and mycoplasma.

63. Tissues are stored in liquid nitrogen, temperature must not rise above -130°C, otherwise crystals may form.

64. Totipotency is the capacity of a cell or plant to develop into a complete plant.

65. Transferred cells are selected with the help of a reporter gene.

66. Transgenes express their character in transgenic plants only for a few generations, a phenomenon called transgene silencing.

67. Vanderplank gave the terms vertical and horizontal resistance.

68. A variety identical in genotype except for one gene is called an isogenic line.

69. Verminator technology is an alternative to terminator technology, developed in the United Kingdom.

70. Vertical resistance breaking to new pathogen races causing huge economic loss is called the Vertifolia effect.

71. Vertical resistance shows resistance to some races of pathogens more than others.

72. Will is a variety of barley resistant to green bug.

73. Without cell division, two or more successive rounds of DNA replication is known as endoreduplication.

74. YieldGuard and Maximizer are transgenic varieties of maize.