Multiple Choice QuestionsVirus was discovered by whom
Stanley
Ivanowski
Herelle
Beijerinck
B.
Ivanowski
Ivanoski reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filter-candle. Bacteria are retained by such filters, a new world was discovered: filterable pathogens. However, Ivanovski probably did not grasp the full meaning of his discovery. Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic. He showed that the incitant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria. Ivanovski and Beijerinck brought unequal but decisive and complementary contributions to the discovery of viruses.
Electron microscope is based on the principle of
electromagnetic theory
resolution of glass lenses
magnification of glass lenses
refraction of light
Lichens are described as indicator of
air pollution
water pollution
soil pollution
agriculture productivity
Which one of the following viruses contains is a DNA and RNA?
Cyanophage
Herpes virus
Leuko virus
Polio virus
Identify the correct sequence of events in the viral replication process.
I. Eclipse
II. Maturation
III. Adsorption
IV. Assembly
V. Penetration
VI. Lysis
I, II, III, IV, V, VI
II, I, III, IV, V, VI
III, V, I, II, IV, VI
III, V, VI, IV, II, I
Match the items in column I with those in Column II and choose the correct answer.
| Column I | Column II |
| A. Blue- green algae as biofertilizer | 1. Ectomycorrhiza |
| B. Fungi as biofertilizer | 2. Thiobacillus sp. |
| C. Free living nitrogen fixing bacteria | 3. Anabaena sp. |
| D. Phosphate solubilizing bacteria |
4. Clostridium sp. 5. Azospirillium sp. |
A- 3; B- 1; C- 5; D- 2
A- 5; B- 1; C- 2; D- 4
A- 5; B- 4; C- 1; D- 2
A- 4; B- 2; C- 4; D- 2
lsogamous condition with non-flagellated gametes is found in
Chlamydomonas
Spirogyra
Volvox
Fucus
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