NEET Bioology Previous Papers Chapterwise

21. Which one of the following pairs is not correctly matched? [NEET 2004]
(a) Streptomyces – Antibiotic
(b) Serratia – Drug addiction
(c) Spirulina – Single cell protein
(d) Rhizobium – Biofertilizer
Ans: (b) Rhizobium is a symbotic nitrogen fixing bacteria. Streptomyces is a source for streptomycin. Spirulina is a rich source of vitamin B1 and proteins.
22. Dough kept overnight in warm weather becomes soft and spongy because of [NEET 2004]
(a) absorption of carbon dioxide from atmosphehre
(b) fermentation
(c) cohesion
(d) osmosis
Ans: (b) Cohesion is the force of attraction between similar molecules. Osmosis is the movement of solvent molecules from a region of low solute concentration to a region of high solute concentration through a semipermeable membrane.
23. The term antibiotic was first used by [NEET 2003]
(a) Flemming (b) Pasteur
(c) Waksman (d) Lister
Ans: (c) The term antibiotics was coined by Waksman but the first known antibiotic, penicillin was extracted from fungi Penicillium notatum by Alexander Flemming in 1944. Antibiotics are the chemicals that are produced from the living organisms, used to kill another living organisms. About 2300 antibiotics discovered so far e.g. Streptomycin, Tetracycline etc.
24. During the formation of bread it becomes porous due to release of CO2 by the action of
(a) Yeast (b) Bacteria [NEET 2002]
(c) Virus (d) Protozoans
Ans: (a) Yeast carry out fermentation, releasing CO2 making bread soft and porous. Hence, Saccharomyces is referred to as baker’s yeast.
25. Industrial production of ethanol from starch is brought about by [NEET 2000]
(a) Saccharomyces (b) Lactobacillus
(c) Azotobacter (d) Penicillium
Ans: (a) Yeast helps in ethyl alcohol formation. Lactobacillus is the milk bacteria while is the free living nitrogen fixing bacteria and Penicillium is the source of Penicillin.
26. Which one of the following micro-organisms is used for production of citric acid in industries? [NEET 1998]
(a) Penicillium citrinum
(b) Aspergillus niger
(c) Rhizopus nigricans
(d) Lactobacillus bulgaris
Ans: (b) Aspergillus niger is known as guinea pig of kingdom fungi. The main source of commercial preparation of citric acid is the fermentation of sugar with Aspergillus niger.
27. Yeast Saccharomyces cerevisiae is used in the industrial production of [NEET 1998]
(a) citric acid (b) tetracycline
(c) ethanol (d) butanol
Ans: (c) Yeast performs alcoholic fermentation because of enzyme ‘zymase’. It is used in the production of ethyl alcohol or ethanol.
28. Which one thing is not true about antibiotics? [NEET 1996]
(a) The term “antibiotic” was coined by Selman Waksman in 1942
(b) First antibiotic was discovered by Alexander Flemming
(c) Each antibiotic is effective only against one particular kind of germ
(d) Some persons can be allergic to a particular antibiotic
Ans: (c) ‘Each antibiotic is effective only against one particular kind of germ’ is not correct.
29. The organism, used for alcoholic fermentation, is [NEET 1995]
(a) Pseudomonas (b) Penicillium
(c) Aspergillus (d) Saccharomyces Topics 2: Microbes in production of Biogas/as Bio-control Agents/as Biofertilisers
Ans: (d) Fermentation refers to the breakdown of organic substances, particularly carbohydrates, under anaerobic conditions. Saccharomyces cerevisiae is used for fermenting carbohydrate. The ethyl alcohol and carbon dioxide are formed at the end of the process.
30. Which of the following is wrongly matched in the given table ? [NEET 2016] Microbe Product Application
(a) Trichoderma polysporum Cyclosporin A immunosuppressive drug
(b) Monascus purpureus Statins lowering of blood cholesterol
(c) Streptococcus Streptokinase removal of clot from blood vessel
(d) Clostridium butylicum Lipase removal of oil stains
Ans: (d) Clostridium butylicum is used for butyric acid production
31. The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the [NEET 2016]
(a) Halophiles
(b) Thermoacidiophiles
(c) Methanogens
(d) Eubacteria
Ans: (c) Methanogens are microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are obligate anaerobic ancient and primitive bacteria. They are involved in methanogenesis.
32. Match the following list of microbes and their importance: [NEET 2015 RS]
(A) Saccharomyces cerevisiae
(i) Production of immunosuppressive agents
(B) Monascus Purpureus (ii) Ripening of Swiss cheese
(C) Trichoderma polysporum (iii) Commercial production of ethanol
(D) Propionibacterium sharamanii (iv) Production of blood cholestrol lowering agents
(A) (B) (C) (D)
(a) (iv) (iii) (ii) (i)
(b) (iv) (ii) (i) (iii)
(c) (iii) (i) (iv) (ii)
(d) (iii) (iv) (i) (ii)
Ans: (d) A – (iii), B – (iv), C – (i), D – (ii)
33. Microbe used for biocontrol of pest butterfly caterpillars is [NEET NEET Kar. 2013]
(a) Trichoderma sp.
(b) Saccharomyces cerevisiae
(c) Bacillus thuringiensis
(d) Streptococcus sp.
Ans: (c) Microbial biocontrol agent that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (Bt). They sprayed onto vulnerable plants, where they eaten by the insect larvae. In the gut of the larvae, the toxin is released and the larvae get killed. The bacterial disease will kill the caterpillars, but leave other insects unharmed.
34. Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition [NEET 2012]
(a) Azotobacter (b) Aspergillus
(c) Glomus (d) Trichoderma
Ans: (c) Glomus is endomycorrhiza that helps in absorption of nutrition specially phosphorus from soil.
35. A nitrogen-fixing microbe associated with Azolla in rice fields is : [NEET 2012]
(a) Spirulina (b) Anabaena
(c) Frankia (d) Tolypothrix
Ans: (b) Anabaena azollae resides in the leaf cavities of the fern Anabaena. It fixes nitrogen. A part of the fixed nitrogen is excreted in the cavities and becomes available to the fern. The decaying fern plants release the same for utilization of the rice plants.
36. In gobar gas, the maximum amount is that of [NEET 2012M]
(a) butane (b) methane
(c) propane (d) carbon dioxide
Ans: (b) In gobar gas the maximum amount of methane which is produced by methanogenic bacteria. Gobar gas is a gas mixture which is generated when organic compounds are fermented in the absence of air (anaerobic fermentation). Biogas contains 50% – 70% methane, 30% – 40% carbon dioxide, and traces of hydrogen, hydrogen sulphide and nitrogen. Methane is a combustible gas, which means it can be burned. It can be used as a fuel for cooking and lighting.
37. An organism used as a biofertilizer for raising soyabean crops is [NEET 2011]
(a) Azotobacter (b) Azospirillum
(c) Rhizobium (d) Nostoc
Ans: (c) Rhizobium is a nitrogen fixing bacteria, which acts as a biofertilizer in soil to produce soyabean crops.
38. Which one of the following help in absorption of phosphorus from soil by plants? [NEET 2011]
(a) Glomus (b) Rhizobium
(c) Frankia (d) Anabaena
Ans: (a) Glomus aggregatum is a mycorrhizal fungus used as a soil inoculant in agriculture and horticulture. Its purpose is to increase the surface area of roots for nutrient absorption like phosphorus.
39. Which one of the following is not a biofertilizer? [NEET 2011]
(a) Agrobacterium (b) Rhizobium
(c) Nostoc (d) Mycorrhiza
Ans: (a) Agrobacterium is a soil borne pathogen responsible for affecting many higher species of plant. But Rhizobium, Nostoc and Mycorrhiza are biofertilizers.
40. A common biocontrol agent for the control of plant diseases is [NEET 2010]
(a) Baculovirus
(b) Bacillus thuringiensis
(c) Glomus
(d) Trichoderma
Ans: (d) A common biocontrol agent for control of plant diseases is Trichoderma. Trichoderma is a tree living fungus that exert biocontrol over several plant pathogens for the control of plant diseases. It is the natural method of pest and pathogen control.