Biology · Environmental Studies

Microbiology and Nitrogen Cycle

950 Questions

This hub focuses on microbiology and the nitrogen cycle, covering essential concepts about bacteria and soil microbes. Topics include nitrogen fixation, bacterial structures, and soil microbial processes. These concepts are frequently tested in general science sections of various competitive exams.

Nitrogen fixing bacteriaGram-positive bacteriaBacterial flagellaDenitrifying bacteriaAmmonia conversion processBacterial resting spores

Microbiology and Nitrogen Cycle Questions

Multiple choice

Correctly match the following pairs given in two columns: Column-I Column-II

  1. Clostridium A. Fixes nitrogen
  2. Yeast B. Produces muscular paralysis
  3. Myxomycetes C. group of fungi that form mutual beneficial relation with other plants
  4. Rhizobium D. causes conversion of carbohydrates to carbon dioxide & alcohol
  5. Mycorrhizae E. have both dry & wet spores

  1. 1A, 2B, 3C, 4D, 5E

  2. 1B, 2D, 3E, 4A, 5C

  3. 1C, 2A, 3B, 4E, 5D

  4. 1D, 2C, 3A, 4B, 5E

  5. 1E, 2A, 3D, 4C, 5B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Clostridium is rod-shaped bacteria that is toxic in nature & causes flabby muscular paralysis; yYeast is eukaryotic microorganism (fungi) used in fermentation to convert carbohydrates to carbon dioxide & alcohol; myxomycetes are found in forest areas on dead leaves & have both dry & wet spores; Rhizobium is gram-negative bacterium of soil that helps in nitrogen fixing; Mycorrhizae are the group of fungi that form mutual beneficial relation with other plants.

Multiple choice

Assertion(A): Nitrogen fixation is achieved industrially by the Haber Bosch process in which H2 and N2 are mixed together at high temperature and pressure in the presence of a catalyst to form NH3.
Reasoning(R): Fertilizers like ammonium nitrites are prepared by this process.

  1. Both Assertion and Reasoning are true and R is the correct explanation of A.

  2. Both Assertion and Reasoning are true but R is not the correct explanation of A.

  3. A is true and R is false.

  4. Both A and R are false.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Both Assertion and Reasoning are true and related. Fertilizers like ammonium nitrites are prepared by this process.

Multiple choice

Consider the following statements and choose which of the following are incorrect about the nitrogen cycle?

A. Biological nitrogen fixation amounts to more than 60% of the annual total fixation. B. Nitrogen fixation is achieved industrially by Haber Bosch process. C. Nitrification involves the reduction of nitrogen compounds. D. Decomposers carry out deamination resulting in the release of nitrogen. E. Nitrosomonas reduces ammonia to nitrites.

  1. A and B

  2. B, C and E

  3. C, D and E

  4. D and E

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nitrification involves oxidation of nitrogen compounds.  The decomposers carry out a process called deamination which results in the release of ammonia. Ammonia undergoes oxidation to give nitrates.

Multiple choice

Which of the following bacteria are called gliding bacteria?

  1. Mycobacteria and Myxobacteria

  2. Mycobacteria and Cytophagales

  3. Myxobacteria and Cytophagales

  4. Cytophagales and Rickettsiae

  5. Rickettsiae and Chlamydiae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Myxobacteria and Cytophagales are called gliding bacteria on the basis of their gliding mobility on solid surfaces.

Multiple choice

Which of the following is a set of acidophiles?

  1. Sulfolobus, Lactobacillus, Aspergillus

  2. Pseudomonas, Euglena, Paramecium

  3. Sulfolobus, Euglena, Lactobacillus

  4. Sulfolobus, Lactobacillus, Aspergillus

  5. Euglena, Lactobacillus, Pseudomonas
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All are acidophiles. 

Multiple choice

Which of the following is a set of neutrophiles only?

  1. Alicyclobacillus, Ferroplasma and Sulfolobus

  2. Escherichia, Euglena and Paramecium

  3. Sulfolobus, Escherichia and Euglena

  4. Euglena, Natronobacterium and Paramecium

  5. Alicyclobacillus, Escherichia and Paramecium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Escherichia, Euglena and Paramecium: All are neutrophiles (optimum growth between pH 5.5 and 8.0).