Quick Revision Botany And Zoology Part 4

QUICK REVISION BOTANY AND ZOOLOGY PART 4 1. Elisa test is a test which confirms presence of HIV or AIDS virus 2. Pure culture or Axenic culture is a culture in which an organism or cell is cultured in an environment free from any other living organism 3. Dianoflagellates are unicellular algae with celluloic cell wall which reproduce asexually sexual reproduction is absent e.g.Gonyaulax causes red tides in sea or sea surface becomes red. 4. Biogas or gobar gas is produced by anaerobic fermentation of biomass. It contains 5070% methane, 30-40% CO2, and traces of hydrogen. Beside dung Eichomia crassipes is extensively utilized for biogas production. Generally cellose digestion is the slowest process and rate limiting step in biogas production. 5. Sporopollenin is found in outer wall exine of pollen grainand is secreted by Ubisch bodies of tapetal cells. It is most resistant chemical substanced of plant kingdom. It is resistant to physical and biological decomposition. So pollen is preserved in fossil deposits for long period. Existence of coal and petroleum may be detected by fossil deposits of pollen grain(Palaeobotany). 6. Herbarium is a place where dried plant specimens are kept for reference. The herbarium specimens preserved in Indian National Herbarium at have been arranged according the system of Bentham and Hooker. 7. Cocos nucifera (coconut) has been regarded as man's most useful tree or Nature's greatest gift to mankind, Kalpa Vriksha and tree of Heaven: Every part of this plant is used. 8. Fluoro carbons, Aerosols, Freon gas methane and nitrogen oxides destroy or deplete ozone layer in startosphere. Which permets more harmful U.V. radiations to reach earth surface Super Sonic air crafts cause major destruction of ozone layer thinning or destruction of ozone layer is known as ozone hole The ozone helps in absorbing the U.V.rays. CFC can be removed by lcceleaning sun rays reacts with CFC to release chlorine atom which is ozone eater. Each chlorine atom can destroy thousand of molecule of ozone. The process of depletion of speed up in the ice cold temperature, that's why ozone depletion, is specially pronounced over the South pole Antartica. Ozone hole in Antartica is very prominent generally during the month of september due to low temperature. 9. Petroleum plants are some plants and Apocynaceae which convert photosynthesis into latex, the liquid hydrocarbons present in the latex of these plants are promising substitute for petroleum (liquid fuel). 10. Opiatic narcotics are opium, morphine or heroine which are obtained from latex of immature fruits or capsule of 'Papaver sominiferum Opium or morphine suppresses the brain function fna dalso used as pain killer. Heroine is also known as brown sugar. Opium contains alkaloids morphine, codeine and papaverine. 11. Hallucinogens like Bhang, Charas and Ganja are three in toxicating drugs, are obtained from cannabis indica. The drugs marijuana and hashish are derived from Cannabis sativa. These drugs change persons' thoughts, feeling and perceptions. 12. Resolving power of human eye is 100u. 13. Resolving power of light miroscope is 0.3. 14. Light microscope magnify the object upto 2000 times. 15. Resolving power of electron microscope (EM) is 5A (For cell study 10-20A). 16. EM can magnify the image 250,000 times. 17. EM was invented by Knoll and Ruska. 18. The cell was discovered by R. Hooke in 1665. 19. Cell theory was formulated by Schleiden and Schwann in 1839. 20. R. Virchow said "Omnis cellula e cellula (all cells arise from preexisting cells). 21. Virus is exception to cell theory. Purkinje named protoplasm. Smallest cell is of PPLO (Pleuro-pneumonia like organism) e.g. Mycoplasma gallisepticum. 1u in diameter. 22. Feulgen stain in specific stain for staining nucleic acids (DNA). 23. Largest-cell in plants is fibre of Boehmeria nivea or Acetabularia (Unicellular algae). 24. Huxley called protoplasm as Physical basis of life. 25. Janus green B is specific stain for mitochondria. Singer and Nicholson proposed fluid mosaic model of plasma membrane 26. Mitochondria discovered by Kollikar, & the term bioplast to mitochondrai was given by Altman while the name mitochondria was given by Benda. 27. Only one mitochondrion per cell has been reported in alga e.g.Microsterius. 28. Mitochondria are very rich in catabolic (oxidative ) enzymes. 29. The mitochondria produce energy, so they called as power house of the cell. 30. Chloroplasts (plastids) are largest cell organelle of the the plant cells. 31. Chloroplasts and mitochondria are regarded as semiautonomous organelle. 32. Three main type of plastids are chloroplasts (green plastids). leucoelasts (colourless plastids) and chromoplast (coloured plastids). 33. Ribosomes are the centre of protein synthesis. 34. Ribosomes are smallest membraneless cell organelle and are strongly negative 35. Palade cained the term ribosome. 36. Depending upon the size and sedimentation coefficient ribosomes are of two types 80S and 70S. 37. Lysosomes were first discovered by De Duve. 38. Lysosomes are known as suicidal bags of cell. Matrix of lysosomes is rich in hydrolytic enzymes which are active in acidic pH (PH5). 39. Golgi complex are also known by the name dictyosomes. 40. Golgi complex is involved in cell plate formation, secretion (enzymes of lysosomes and peroxisomes) and glycosidation of lipids and protein (formation of glycolipids and glycoproteins). 41. Endoplasmic reticulum (ER) is of network of membrane bound cavities. 42. ER are of two types-rough (granular) ER with ribosomes and smooth (agranular) ER without ribosomes. 43. Rough ER help in protein synthesis and smooth ER help in steroid or chiolesterol synthesis. 44. Glyoxisomes contain the enzymes of glyoxylate cycle, by which fats or lipids are converted into sugars. 45. Photorespiration takes place in peroxisomes 46. The term centrosome was coined by T. Boveri (1888) & described centriole. 47. Centrosomes are found in animals cells, some algae and fungi. 48. Centrosomes contribute in aster formation at the time of cell division and have fibrillar organization (9+0). 49. Eukaryotic flagella orcilia have 9+2 fibrillar organization 50. Cystolith is deposition of calcium carbonate in cells. 51. Raphides are deposition of calcium oxalate in cells. 52. Nucleus was discovered by R. Brown. It is known as controlling tower of cell. 53. Nucleus is absent in R.B.C sieve tubes, xylem tracheids, xylem vessels, fibres, stone cells and other dead cells. 54. Nucleolus is membraneless. 55. Nucleolus is mainly composed of RNA and phosphoprotein 56. Nucleolus helps in biogenesis of rRNA and ribosomes and also helps in spindle formation. 57. In 1905 Sutton and Boveri proposed chromosome theory of heredity according to which chromosomes are vehicle of heredity. 58. The term chromosome was given by Waldeyer (1888). 59. The nucleic acid (DNA) was discovered by F. Miescher (1869). 60. Nucleic acids consist of sugar (Pentose), nitrogenous bases and phosphoric acid. 61. Histone proteins are attached to the DNA at an angle of 30A 62. Avery, Maclod and Mc Carthy (1994) proved that DNA is genetic material. 63. Watson and Crick (1953), wilkins & Franklin proposed the widely accepted double helex model for DNA. 64. Each strand of double helix is formed by sequence of nucleotides linked together by phosphodiester bonds. 65. The two strands of DNA are antiparallel and complementary 66. One turn of the helix measures about 34Ao and 10 pairs of nucleotides are placed at regular interval of 3.4A. 67. The diameter of DNA helix is roughly 20A. 68. Mostly RNA is single stranded. RNA (Nongenetic) is of three types-mRNA, RNA, RNA. 69. Ribosomal RNA (TRNA) is found in ribosome and nucleolus. 70. Molecuies of tRNA 25000 to 30,000 are smallest. 71. The specific site on the tRNA which attaches to the mRNA is a sequence of three bases called anticodon. 72. Messenger RNA (mRNA) crries genetic information from DNA (Nucleus) to the cytoplasm where protein in synthesized, 73. Transfer RNA (ERNA) picks up a specific activated amino acid from the cytoplasm and transfer it to the site of protein synthesis 74. Replication of DNA is semiconservative in E.coli. 75. Synthesis of DNA takes place in S phase of interphase of cell cycle. 76. crossing over in chromosomes takes place at pachytene stage, of prophase 1 of meisosis 1. 77. Meiosis is the only means for restoring the chromosome number from generation to generation. 78. Initiating codons are AUG of GUG and terminating codons are UAA, UAG and UGA. 79. A process, where in nucleus, chromosome duplication occur without the division of nucleus, is called endomitosis and endopolyploidy. 80. After cellulose, lignin is most abundant plant polymer in wood of trees. 81. Phragmoplast is the cell plate formed during cytokinesis of plant cells. 82. Michaelis constant (Km) of an enzyme is the substrate concentration at which the reaction attains half of its maximum velocity. It is measure of the affinity of the enzymes for its substrate. The lower is the Km, the higher is the substrate affinity of the enzyme. 83. Study of algae is called as Phycology or Algology. 84. M.O.P.Iyengar is considered as the father of India Phycology 85. Red snow is alpine region is due to presence of alga e.g. Haematococcus nivalis. 86. Parasitic algae are Cephaleuros (green algae) and Harveyella (Red algae). 87. Red rust of tea and coffee is caused by Cephaleuros. 88. The red colour of red sea is due to blue green algae e.g. Trichodesmium erythrae. 89. Water bloom is caused due to excessive growth of blue green algae such as lyngbya, Microcytis, Anabaena. 90. N2, fixing blue green algae are Spinilina, Cylindrospermum, Aulosira, Anabaena and Nostoc which are commonly found in paddy fields 91. Commercially Agar Agar is obtained from red algae like Gelidium, Gracilaria Gigartina. 92. Carragenin used in cofectionary, cosmetics etc. is obtained from Chondrus crispes (Irish moss) red algae. 93. Sea kelps e.g. Laminaria Sargassum are useful for curing goitre. 94. Chlorella is used in space flight for O2, and food. 95. Heterocysts are N2 fixing seats or bodies in blue green algae. 96. Most primitive algae are members of cyanophyceae or myxophyceae which have incipient nucleus. 97. Green algae resemble with other green lants in having chlorophyll a and chlorophyll b. 98. Brown algae have chlo a cand unique brown pigment fucoxanthin 99. Ulothrix is fresh water, filamentous green algae, consist of hold fast, vegetative intercalary cells and apical cell. 100. Chloroplast in a cell of Ulothrix is C or collar or girdle shaped with few pyrenoids.