MCQOPTIONS
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MCQOPTIONS
This section includes 14620 Mcqs, each offering curated multiple-choice questions to sharpen your NEET knowledge and support exam preparation. Choose a topic below to get started.
| 8601. |
If all decomposers are removed from an ecosystem, what will happen [RPMT 1995] |
| A. | All consumers will die |
| B. | Energy cycle will be affected |
| C. | Balance of biogeochemical cycle will be disturbed |
| D. | Only herbivores will die |
| Answer» D. Only herbivores will die | |
| 8602. |
Which of the following abundantly occurs in pond ecosystem [RPMT 1995] |
| A. | Producer |
| B. | Consumer |
| C. | Top consumer |
| D. | Decomposers |
| Answer» B. Consumer | |
| 8603. |
The bacteria which attack dead animals are |
| A. | First link of the food chain and are known as primary producers |
| B. | Second link of the food chain and are herbivorous |
| C. | Third link of the food chain and are tertiary consumers |
| D. | The end of food chain and are decomposers |
| Answer» E. | |
| 8604. |
What energy percentage can be captured by the organisms of next trophic level [CBSE PMT 1999] |
| A. | 0.2 |
| B. | 0.3 |
| C. | 0.9 |
| D. | 0.1 |
| Answer» E. | |
| 8605. |
Carnivores are [MP PMT 1993] |
| A. | Usually primary consumers |
| B. | Usually secondary consumers |
| C. | Usually secondary or tertiary consumers |
| D. | Usually decomposers rather than consumers |
| Answer» D. Usually decomposers rather than consumers | |
| 8606. |
In forest ecosystem, pyramid of number is [MP PMT 1993] |
| A. | Upright |
| B. | Inverted |
| C. | Any of the two |
| D. | None of the above |
| Answer» B. Inverted | |
| 8607. |
Ecosystem creates [MP PMT 1993] |
| A. | Food chain |
| B. | Food web |
| C. | Both the above |
| D. | None of the above |
| Answer» C. Both the above | |
| 8608. |
Ecosystem has two components [MP PMT 1993, 98, 99; BHU 2000] |
| A. | Plants and animals |
| B. | Weeds and trees |
| C. | Biotic and abiotic |
| D. | Frog and men |
| Answer» D. Frog and men | |
| 8609. |
Which must be preserved in an ecosystem, if the system is to be maintained [JIPMER 1994; Kerala PMT 2004] |
| A. | Producers and carnivores |
| B. | Producers and decomposers |
| C. | Carnivores and decomposers |
| D. | Herbivores and carnivores |
| Answer» C. Carnivores and decomposers | |
| 8610. |
The character of an ecosystem is determined by the environmental factor which is shortest supply. This is the [CBSE PMT 1994] |
| A. | Law of minimum |
| B. | Law of diminishing returns |
| C. | Law of limiting factors |
| D. | Law of supply and demand |
| Answer» B. Law of diminishing returns | |
| 8611. |
The symbiotic nitrogen fixing bacteria present in root nodules of legumes belongs to genus [DPMT 1982; MP PMT 1989; DPMT 1993; CPMT 1998; CBSE PMT 1999; Pb. PMT 1999; BVP 2002; Kerala CET 2003; MHCET 2004] |
| A. | Xanthomonas |
| B. | Pseudomonas |
| C. | Rhizobium |
| D. | Acetobacter |
| Answer» C. Rhizobium | |
| 8612. |
Nitrogen fixing bacteria are associated with [EAMCET 1981; MP PMT 1988] |
| A. | Leguminasae |
| B. | Cruciferae |
| C. | Gramineae |
| D. | Malvaceae |
| Answer» D. Malvaceae | |
| 8613. |
Antibiotics are mostly obtained from [CPMT 1971, 77, 79; JIPMER 1987] |
| A. | Bacteria (Actinomycetes) |
| B. | Virus |
| C. | Angiosperms |
| D. | Fungi |
| Answer» B. Virus | |
| 8614. |
Root nodules contain [DPMT 1993] |
| A. | Nostoc |
| B. | Chlorobium |
| C. | Rhizobium |
| D. | Azotobacter |
| Answer» D. Azotobacter | |
| 8615. |
Which of the following is a free living nitrogen fixing bacteria present in the soil [J & K CET 2005] |
| A. | Pseudomonas |
| B. | Rhizobium |
| C. | Azotobacter |
| D. | Nitrosomonas |
| Answer» D. Nitrosomonas | |
| 8616. |
For retting of jute the fermenting microbe used is [CBSE PMT 2005] |
| A. | Methophilic |
| B. | Butyric acid bacteria |
| C. | Helicobactor pylori |
| D. | Streptococcus lactin |
| Answer» C. Helicobactor pylori | |
| 8617. |
All of the following statements concerning the actinomycetous filamentous soil bacterium Frankia are correct except that Frankia [CBSE PMT 2005] |
| A. | Can induce root nodules on many plant species |
| B. | Cannot fix nitrogen in the free-living state |
| C. | Cannot fix specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hapanoids |
| D. | Like Rhizobium, it usually infects its host plant through root hair deformation and stimulates cell proliferation in the host's cortex |
| Answer» C. Cannot fix specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hapanoids | |
| 8618. |
Which bacteria is responsible for the reduction of nitrates in to nitrogen, in soil [Orissa JEE 2005] |
| A. | Nitrosomonas |
| B. | Pseudomonas |
| C. | Rizobium |
| D. | Clostridium |
| Answer» B. Pseudomonas | |
| 8619. |
A substance that causes the disintegration of bacteria is |
| A. | Bacteriocin |
| B. | Bacterin |
| C. | Barophile |
| D. | Bacteriolysin |
| Answer» E. | |
| 8620. |
Which of the bacterium is useful in preparing Idli [BVP 2003] |
| A. | Leuconostoc mesenteroides |
| B. | Clostridium |
| C. | Both (a) and (b) |
| D. | None of the above |
| Answer» B. Clostridium | |
| 8621. |
Milk is changed into curd by [MP PMT 2002] |
| A. | Acetobactor aceti |
| B. | Bacillus megatherium |
| C. | Xanthomonas citri |
| D. | None of these |
| Answer» E. | |
| 8622. |
Biofertilizers include [J & K CET 2002] |
| A. | Nitrogen fixing bacteria |
| B. | Nitrogen fixing cyanobacteria |
| C. | Mycorrhiza |
| D. | All of these |
| Answer» E. | |
| 8623. |
The bacteria (Clostridium botulinum) that cause botulism are [KCET 2001] |
| A. | Obligate aerobes |
| B. | Facultative aerobes |
| C. | Obligate anaerobes |
| D. | Facultative anaerobes |
| Answer» D. Facultative anaerobes | |
| 8624. |
Plasmid is used as carrier because [CBSE PMT 2000] |
| A. | It has antibiotic resistance genes |
| B. | Its both ends are replicating points |
| C. | It can go between eukaryotic and prokaryotic cells |
| D. | It is circular DNA which has capacity to bind eukaryote DNA |
| Answer» E. | |
| 8625. |
For the production of which of the following, the activity of the fungus or micro-organisms is not required [MP PMT 1991] |
| A. | Casein |
| B. | Panir (Cheese) |
| C. | Curd |
| D. | Wine |
| Answer» B. Panir (Cheese) | |
| 8626. |
Which is not help in \[{{N}_{2}}\] fixation [RPMT 1999] |
| A. | Anabaena |
| B. | Nostoc |
| C. | Oscillatoria |
| D. | Rhizobium |
| Answer» D. Rhizobium | |
| 8627. |
Fermentation is by [RPMT 1999] |
| A. | All micro organism |
| B. | All fungi |
| C. | All bacteria |
| D. | Some fungi and some bacteria |
| Answer» E. | |
| 8628. |
Which of the following is non-symbiotic biofertilizer [CBSE PMT 1998] |
| A. | VAM |
| B. | Azotobacter |
| C. | Anabaena |
| D. | Rhizobium |
| Answer» C. Anabaena | |
| 8629. |
Which bacteria convert ammonium salts into nitrite [CPMT 1998] |
| A. | Nitrobacter |
| B. | Nitrosomonas |
| C. | Azotobacter |
| D. | None of these |
| Answer» B. Nitrosomonas | |
| 8630. |
The bacteria found in nodules of family leguminoseae are [CPMT 1998] |
| A. | Rhizobium |
| B. | Azotobacter |
| C. | Nitrobacter |
| D. | None of these |
| Answer» B. Azotobacter | |
| 8631. |
Which of the following soil microorganisms breaks down plant and animal protein into ammonia [KCET 1998] |
| A. | Bacillus vulgaris |
| B. | Nitrosomonas |
| C. | Pseudomonas |
| D. | None of the above |
| Answer» C. Pseudomonas | |
| 8632. |
Which of the following is used to cure off the bitterness of tea leaves [CPMT 1999; JIPMER 2001] |
| A. | Bacillus subtilis |
| B. | B. megatherium |
| C. | B. lactis |
| D. | B. mycococcus |
| Answer» B. B. megatherium | |
| 8633. |
One of the useful activities of several bacteria is [MP PMT 1998] |
| A. | Nitrogen fixation |
| B. | Nitrification |
| C. | Operation of biogeochemical cycles |
| D. | All of the above |
| Answer» D. All of the above | |
| 8634. |
Bacteria which directly convert atmospheric nitrogen into nitrogen compounds are called [AFMC 1996] |
| A. | Denitrifying bacteria |
| B. | Putrefying bacteria |
| C. | Nitrogen fixing bacteria |
| D. | Nitrifying bacteria |
| Answer» D. Nitrifying bacteria | |
| 8635. |
Which of the following groups of plants are highly useful in increasing soil fertility [CBSE PMT 1993] |
| A. | Red algae |
| B. | Fungi |
| C. | Bacteria |
| D. | Bryophytes |
| Answer» D. Bryophytes | |
| 8636. |
Nitrifying bacteria are those which can convert [MP PMT 1995] |
| A. | Atmospheric nitrogen into ammonia |
| B. | Ammonia into nitrites |
| C. | Nitrites into nitrates |
| D. | Nitrates into ammonia |
| Answer» D. Nitrates into ammonia | |
| 8637. |
Root nodules for nitrogen fixation in nonleguminous trees are produced by species of the genus [BHU 1994] |
| A. | Rhizobium |
| B. | Azatobacter |
| C. | Frankea |
| D. | Thiobacillus |
| Answer» C. Frankea | |
| 8638. |
Which one of the following bacteria has potential for nitrogen fixation [MP PMT 1995; Bihar MDAT 1995] |
| A. | Nitrosomonas |
| B. | Nitrobacter |
| C. | Nitrosococcus |
| D. | Rhizobium |
| Answer» B. Nitrobacter | |
| 8639. |
The biological process carried on by Rhizobium is called [MP PMT 1995] |
| A. | Nitrification |
| B. | Ammonification |
| C. | Nitrogen fixation |
| D. | Fermentation |
| Answer» E. | |
| 8640. |
A large number of organic compounds can be decomposed by [CBSE PMT 1995] |
| A. | Chemoorgano |
| B. | Pseudomonas |
| C. | Acetobacter |
| D. | Mycoplasma |
| Answer» D. Mycoplasma | |
| 8641. |
The main role of bacteria in the carbon cycle involves [CBSE PMT 1998; AIIMS 2000] |
| A. | Photosynthesis |
| B. | Assimilation of nitrogenous compounds |
| C. | Chemosynthesis |
| D. | Digestion or breakdown of organic compounds |
| Answer» D. Digestion or breakdown of organic compounds | |
| 8642. |
Wine turns sour because of [CPMT 1994] |
| A. | Heat |
| B. | Aerobic bacteria |
| C. | Anaerobic bacteria |
| D. | Exposure to light |
| Answer» E. | |
| 8643. |
A suspension of killed or attenuated bacteria useful for artificial immunization is |
| A. | Bacteriocin |
| B. | Bacteriolysin |
| C. | Bacterin |
| D. | Barophile |
| Answer» B. Bacteriolysin | |
| 8644. |
The bacterial decomposition of nitrogenous organic compounds in the absence of abundant oxygen usually results in the formation of substance of offensive odour, chiefly sulphur compounds. Such anaerobic decomposition is called |
| A. | Putrefaction |
| B. | Nitrification |
| C. | Denitrification |
| D. | N2 fixation |
| Answer» E. | |
| 8645. |
Which of the following is free-living aerobic non- photosynthetic nitrogen fixing bacterium [CBSE PMT 1997; BHU 2003] |
| A. | Rhizobium |
| B. | Azotobacter |
| C. | Nostoc |
| D. | Azospirillum |
| Answer» C. Nostoc | |
| 8646. |
The decomposition of organic compounds in the presence of \[{{O}_{2}}\] without the development of odoriferous substance is |
| A. | Nitrifixation |
| B. | Decay |
| C. | Denitrifixation |
| D. | Nitrogen fixation |
| Answer» D. Nitrogen fixation | |
| 8647. |
A compound which is produced by an organism and inhibits the growth of other organism is called [DPMT 1992] |
| A. | Antiseptic |
| B. | Anticoagulant |
| C. | Antibiotic |
| D. | Anti-allergic |
| Answer» C. Antibiotic | |
| 8648. |
Waksman got the Nobel Prize for the discovery of [DPMT 1992] |
| A. | Penicillin |
| B. | Streptomycin |
| C. | Chloromycetin |
| D. | Neomycin |
| Answer» E. | |
| 8649. |
The denitrification means [DPMT 1990; CPMT 2003] |
| A. | Reduction of \[N{{O}_{2}}\] to ammonia form by bacteria in the soil |
| B. | Oxidation of ammonia to nitrate form |
| C. | Conversion of ammonia to amino acids |
| D. | Conversion of ammonia and nitrates to gaseous nitrogen in the soil |
| Answer» E. | |
| 8650. |
Micro-organisms are used in |
| A. | Sewage disposal |
| B. | Biological control of diseases |
| C. | Biological warfare |
| D. | All the above |
| Answer» C. Biological warfare | |