Answer :
1. Answer : (d) Free infectious RNA
Explanation : Theodor Otto Diener discovered a capsid-free infection DNA, which is the causative agent of the potato spindle tuber disease. It was not a virus, but a completely unique agent, which consists solely of a brief strand of single-stranded RNA without a protein capsid.
2. Answer : (c) Linnaeus
Explanation : The static concept of species was given by Linnaeus in Systema Naturae.
3. Answer : (d) T. gambiense
Explanation : Sleeping sickness is caused by two types of parasites Trypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. T b rhodesiense causes the more severe form of the illness.
4.Answer : (a) Lichens do not grow in polluted areas.
Explanation : Lichens grow in all environments except the high seas, on the tissues of live animals, and in highly polluted areas.
5.Answer : (c) Agaricus
Explanation : In Neurospora, the spores are endogenously formed in a sac-like structure called ascus.
6. Answer : (d) RNA molecules without a protein coat
Explanation : Viroids are the smallest self replicating RNA particles which are devoid of protein coat while viruses can have either RNA or DNA molecules encapsulated in a protein coat. Viroids were first discovered by Diener (1971). They consist of only the nucleic acid without a protein coat.
7. Answer : (d) Glycocalyx
Explanation : The component of bacterial cells that provide sticky character to the cell is Glycocalyx. The glycocalyx is a carbohydrate-enriched coating present outside of prokaryotic cells.
8. Answer : (b) Mycoplasma
Explanation : Mycoplasma is the smallest living known cell. It is prokaryotic, devoid of a cell wall, and can live without oxygen. It is pathogenic to both plants and animals.
9. Answer : (a) Plasma membrane
Explanation : A cellular component in the eubacteria that resembles the eukaryotic cell is the plasma membrane.
10.Answer : (d) Bacteria
Explanation : Mesosomes are found in several heterotrophic bacteria. These invaginated structures are in the form of vesicles, tubules of lamellar whorls.
11.Answer : (a) Plant viruses
Explanation : Plant viruses often contain parasites of their own, referred to as satellites. Satellite RNAs are highly dependent on their helper virus for both replication and encapsidation. Their size vary from 194 to 1500 nucleotides (approx.)
12. Answer : (a) Deuteromycetes
Explanation : Deuteromycetes are the imperfect fungi which include all those fungi in which the sexual stage is either absent or not known. Some of the members are saprophytes or parasites while most of them are decomposers of litter and help in the cycling of minerals.
13. Answer : (b) Aerobic bacteria
Explanation : When exposed to the air, the bacteria tend to change the sugar to acetic acid. This process is known as aerobic fermentation. The resultant wine is not just wine it is wine vinegar.
14.Answer : (d) Viroids
Explanation : In 1971, studies of the potato spindle tuber disease showed that it was caused by a small, naked, single-stranded, circular molecule of infectious RNA, which was called a viroid. Viroids have been found to be the cause of several dozen plant diseases.
15. Answer : (b) Thermoacidophiles
Explanation : Thermophiles are a group of heat loving microbes thriving at high temperature usually more than \(45^{\circ} C\)
16. Answer : (c) Dinoflagellates
Explanation : Some algae species, like the dinoflagellate Karenia brevis, color the ocean surface a deep red, inspiring the name “red tide.” But not all red tides are red and not all of them even become dense enough to color the water. There are also “brown tides” which can be damaging as well.
17. Answer : (c) Fungi
Explanation : toadstool, any of various inedible or poisonous species of mushrooms (kingdom Fungi).
18. Answer : (b) Asexual reproduction
Explanation : Spore Formation is a method in Asexual Reproduction. Many Spores are stored in sacs called Sporangia. When Sporangia burst; minute single-celled, thin or thick-walled structures called spores are obtained. Under suitable conditions, they develop into a new Plant.
19.Answer : (b) It has siliceous walls
Explanation : Diatoms have unique double shells made up of opaline silica.
20. Answer : (c) Rice
Explanation : The use of Bio-fertilizers like Azolla not only increases the rice productivity but also improves the long-term soil fertility.
21. Answer : (a) Kew
Explanation : The largest herbaria in the world (each with 7 to 9.5 million specimens) are located at the Museum of Natural History in Paris, the Royal Botanic Gardens, Kew, in England, the New York Botanical Garden, and the Komarov Botanical Institute, in St. Petersburg, Russia.
22. Answer : (a) Methanogens
Explanation : Methanogens bacteria are present in the guts of ruminant animals such as cows and buffaloes. The characteristic smell of cow dungs is due to methane gas produced by this bacteria.
23. Answer : (a) natural system
Explanation : A system based upon a large number of natural characters or traits is natural system of classification.
24. Answer : (a) vibrio
Explanation : Vibrio is a genus of Gram-negative bacteria, possessing a curved-rod (comma) shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood.
25. Answer : (d) sympatric
Explanation : Two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation.
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