

MCQOPTIONS
This section includes 37 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology of Soils knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which of the following is a symbiotic nitrogen fixing bacteria? |
A. | Rhizobium trifolii |
B. | Clostridium pasteurianum |
C. | Azotobacter sp. |
D. | Escherichia coli |
Answer» B. Clostridium pasteurianum | |
2. |
How much time does nitrifying bacteria requires to grow at an incubation of 250 to 300 C? |
A. | 1 day |
B. | 2-3 days |
C. | 15 days |
D. | 1 to 4 months |
Answer» E. | |
3. |
Ammonia oxidizers and nitrite oxidizers are ________________________ |
A. | Gram-negative chemolithotrophs |
B. | Gram-positive chemolithotrophs |
C. | Gram-negative photolithotrophs |
D. | Gram-positive photolithotrophs |
Answer» B. Gram-positive chemolithotrophs | |
4. |
The reduction of sulphates and sulphites to hydrogen sulphide is done by which group of bacteria? |
A. | aerobic sulfate-reducing bacteria |
B. | photosynthetic sulphur bacteria |
C. | anaerobic sulphate-reducing bacteria |
D. | heterotrophic bacteria |
Answer» D. heterotrophic bacteria | |
5. |
The Winogradsky column experiment is done in the dark. |
A. | True |
B. | False |
Answer» C. | |
6. |
Sulphates are reduced to hydrogen sulphide by _____________________ |
A. | Desulfotomaculum sp. |
B. | Thiobacillus thiooxidans |
C. | Photosynthetic sulfur bacteria |
D. | Rhodospirillum |
Answer» B. Thiobacillus thiooxidans | |
7. |
Cysteine breaks down in presence of cysteine desulfurase to give _________________ |
A. | oxaloacetic acid |
B. | sulphuric acid |
C. | pyruvic acid |
D. | glyoxalate |
Answer» D. glyoxalate | |
8. |
Which of the following processes is performed by Thiobacillus thiooxidans? |
A. | converting sulphur to sulphates |
B. | converting sulphur to sulphides |
C. | converting sulphur to sulphites |
D. | converting organic sulphur to inorganic sulphur |
Answer» B. converting sulphur to sulphides | |
9. |
Cellobiose is metabolized directly by many microorganisms. |
A. | True |
B. | False |
Answer» C. | |
10. |
In carbon cycle flow of energy is _________________ |
A. | bidirectional |
B. | linear |
C. | cyclic |
D. | irreversible |
Answer» C. cyclic | |
11. |
Denitrification is carried out |
A. | usually by facultative anaerobes |
B. | predominantly by Pseudomonas spp |
C. | predominantly by Bacillus spp |
D. | all of the above |
Answer» E. | |
12. |
The energy value of biogas is typically |
A. | 400-700 BTU/ft |
B. | 1,000 BTU/ft |
C. | 1500 BTU/ft |
D. | more than 5000 BTU/ft |
Answer» B. 1,000 BTU/ft | |
13. |
Ammonia oxidizers and nitrite oxidizers are ______________ |
A. | Gram-negative chemolithotrophs |
B. | Gram-positive chemolithotrophs |
C. | Gram-negative photolithotrophs |
D. | Gram-positive photolithotrophs |
Answer» B. Gram-positive chemolithotrophs | |
14. |
Fresh air contains approximately ______ percent carbon dioxide by volume. |
A. | 0.01 |
B. | 2 |
C. | 5 |
D. | 0.03 |
Answer» E. | |
15. |
Which among the following are the most important agents for carbon dioxide fixation? |
A. | bacteria |
B. | fungi |
C. | algae |
D. | protozoa |
Answer» D. protozoa | |
16. |
Which of the following are not the features of component II of nitrogenase enzyme complex? |
A. | component II is nitrogenase reductase |
B. | component II is known as the MoFe protein |
C. | contains sulfur |
D. | not active without component I |
Answer» C. contains sulfur | |
17. |
Which of the following is symbiotic nitrogen fixing bacteria? |
A. | Rhizobium trifolii |
B. | Clostridium pasteurianum |
C. | Azotobacter sp. |
D. | Escherichia coli |
Answer» B. Clostridium pasteurianum | |
18. |
Which of the following conditions decreases the level of denitrification? |
A. | Abundance of organic matter |
B. | Acidic pH |
C. | Elevated temperatures |
D. | Availability of oxygen |
Answer» C. Elevated temperatures | |
19. |
How much time does nitrifying bacteria require to grow at an incubation of 250 to 300 C? |
A. | 1 day |
B. | 2-3 days |
C. | 15 days |
D. | 1 to 4 months |
Answer» E. | |
20. |
Agrobacterium is involved in which of the following processes? |
A. | Ammonification |
B. | Nitrification |
C. | Reduction of nitrate to ammonia |
D. | Denitrification |
Answer» E. | |
21. |
Nitrosococcus nitrosus is a nitrite-oxidizing bacteria. |
A. | True |
B. | False |
Answer» C. | |
22. |
Which among the following is not an ammonia-oxidizing bacteria? |
A. | Nitrosomonas europaea |
B. | Nitrosovibrio tenuis |
C. | Nitrospina gracilis |
D. | Nitrosococcus oceanus |
Answer» D. Nitrosococcus oceanus | |
23. |
Alanine gives pyruvic acid on deamination. |
A. | True |
B. | False |
Answer» B. False | |
24. |
The amount of organic material in the forest soil remains approximately the same from year to year. |
A. | True |
B. | False |
Answer» B. False | |
25. |
Cellulose is degraded to cellobiose by the enzyme __________________ |
A. | cellulase |
B. | beta-glucosidase |
C. | hexokinase |
D. | cellulose dehydrogenase |
Answer» B. beta-glucosidase | |
26. |
The dominant mineral particles in most soils are compounds of _____________ |
A. | sodium |
B. | potassium |
C. | magnesium |
D. | iron |
Answer» E. | |
27. |
Parasitism results from competition among organisms for essential nutrients. |
A. | True |
B. | False |
C. | May be |
D. | Can't say |
Answer» C. May be | |
28. |
Which of the following comes under the category of positive association? |
A. | neutralism |
B. | parasitism |
C. | commensalism |
D. | ammensalism |
Answer» D. ammensalism | |
29. |
Fungi produces which of the following inhibitory toxic product? |
A. | cyanide |
B. | fatty acids |
C. | methane |
D. | sulphides |
Answer» B. fatty acids | |
30. |
Lytic enzymes which destroy are secreted by which of the following microorganism? |
A. | fungi |
B. | algae |
C. | staphylococcus |
D. | myxobacteria |
Answer» E. | |
31. |
Which of the following types of association is present among Staphylococcus aureus and Aspergillus terreous? |
A. | antagonism |
B. | mutualism |
C. | parasitism |
D. | commensalism |
Answer» B. mutualism | |
32. |
The degradation of complex molecules in soil by fungi for utilization by bacteria is an example of which type of association? |
A. | Neutralism |
B. | Mutualism |
C. | Commensalism |
D. | Antagonism |
Answer» D. Antagonism | |
33. |
Which among the following is a non-sulfur purple bacteria? |
A. | Rhodomicrobium |
B. | Thiobacillus |
C. | Chromatium |
D. | Chlorobium |
Answer» B. Thiobacillus | |
34. |
The association which involves the exchange of nutrients between two species is referred to as ______________ |
A. | mutualism |
B. | syntrophism |
C. | commensalism |
D. | antagonism |
Answer» C. commensalism | |
35. |
Bacteria are likely to be more prevalent in soils of vineyards, orchards and apiaries. |
A. | True |
B. | False |
C. | May be |
D. | Can't say |
Answer» C. May be | |
36. |
Which among the following develop in the upper portion of the Winogradsky column? |
A. | Sulfate-reducing bacteria |
B. | Green-sulfur bacteria |
C. | Purple-sulfur bacteria |
D. | Thiobacilli |
Answer» E. | |
37. |
Which of the following organisms are known to grow on the surfaces of freshly exposed rocks? |
A. | green algae |
B. | diatoms |
C. | cyanobacteria |
D. | yeast |
Answer» D. yeast | |