Biology · Environmental Studies

Microbiology and Nitrogen Cycle

1,029 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 zoology why classification? nomenclature in classification introduction to plant kingdom history of classification nomenclature of animals

Binomial nomenclature is 

  1. Not applicable to cyanbacteria.

  2. Not accepted by a number of countries.

  3. Universal with one specific name to each organism.

  4. Universal with two specific names to each organism.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Binomial nomenclature system was proposed by Carl Linnaeus for the scientific naming of all the plants and animals. Linnaeus proposed the scientific name of plants in his book 'Species Plantarum'.
  • In binomial nomenclature, each scientific name has two components-generic names (genus) and specific name (species) E.g., Mangifera indica Linn. Mangifera is the genus name and indica is the species name.
So, the correct answer 'Universal with one specific name to each organism'

Multiple choice biology classification of plants monera five kingdoms of living organisms biodiversity and need of classification

Comma shaped bacteria are

  1. Bacilli

  2. Spirilla

  3. Vibrios

  4. Cocci
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • Bacteria having rod-shaped structure are called as Bacilli. Examples include Clostridium tetani, Corynebacterium.
  • Bacteria having spiral shape are called as Spirilla. Examples include Spirillum, Campylobacter.
  • Bacteria having a comma-like single curve in their body are Vibrio. Examples include Vibrio cholerae, Vibrio vulnificus.
  • Bacteria that are round in shape are called as cocci. Examples include Streptococcus pneumoniae, Staphylococcus aureus. 
Thus, the correct answer is 'Vibrios.'

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

Which one of the following statements is correct?

  1. Mostly bacteria are heterotrophic, but some are autotrophic

  2. All bacteria are heterotrophic

  3. All bacteria are autotrophic

  4. All bacteria are photosynthetic
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Most bacteria are heterotrophic, however, a special class of bacteria called cyanobacteria or BGA are autotrophic, that is they can produce there own food. So, the correct option is A. ( Mostly bacteria are heterotrophic, but some are autotrophic )

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

Which of the following is correct?

  1. Bacteria are only autotrophic.

  2. Bacteria are only heterotrophic.

  3. Most bacteria are heterotrophic but few are autotrophic.

  4. Most bacteria are autotrophic but few are heterotrophic.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The bacteria are the prokaryotic organisms which are generally heterotrophic. These bacteria feed on the dead and digested matter. There are certain species of bacterium which is inclusive of the cyanobacteria. These are the blue-green algae which can perform photosynthesis due to the presence of the chlorophyll pigments. The other bacterial species can perform chemosynthesis and can utilise the organic and inorganic compounds as the source of energy. 

Thus, the correct answer is option C. 

Multiple choice biology classification of plants monera five kingdoms of living organisms biodiversity and need of classification

Bacillus subtilis are

  1. Hay bacteria

  2. Nitrifying bacteria

  3. Ammonifying bacteria

  4. Intestinal bacteria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacillus subtilis are also called as hay bacillus. They are gram-positive bacteria. They are commonly found in hay or upper layer of soil. Hence, they are called as hay bacteria. They are also found in the GI tract of ruminants and humans. They are obligate aerobes. 

Thus, the correct answer is 'Hay bacteria.'

Multiple choice biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

Kingdom monera includes

  1. Bacteria

  2. Nitrogen fixing organisms

  3. Cyanophyceae

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Monera is non-nucleated unicellular organisms. They are prokaryotes. They have a cell wall. They have no membrane-bound organelles such as mitochondria, Golgi complex. They lack a true nucleus. Instead, they have nucleoid, genetic material without a nuclear membrane. Examples include Bacteria, cyanophyceae (Blue-Green algae), Nitrogen-fixing organisms etc.

Thus, the correct answer is 'All of the above.'

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Bacteroides are?

  1. Enlarged non-motile cellular bacteria Rhizobium leguminosarum in root nodules of legumes

  2. A bacterial cell infected with viruses

  3. A motile bacterium

  4. Nitrosomonas bacteria in soil
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacteroids are the differentiated, non-motile form of Rhizobium bacteria found within the root nodules of legumes, where they fix nitrogen.

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects

Which of the following is a photo-autotrophic bacterium

  1. Rhodospirillum

  2. Azospirillum

  3. NitrosomonasV

  4. Nitrobacter
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rhodospirillum bacteria is facultative aerobic Photo - autotrophic bacteria use non-sulphur aliphatic organic  compound as donor of $H _{2}$  go,. Propyl alcohol .

$6CO _{2}+12CH _{3}CHOHCH _{3}\overset{Light}{\rightarrow}$

$C _{6}H _{12}O _{6}+12CH _{3}COH _{3}+6H _{2}O$



Multiple choice botany the world of microbes bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Some bacteria are considered plants as they

  1. Are green in colour

  2. Have rigid cell wall

  3. Have chlorophyll

  4. Have stomata
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Some bacteria, such as cyanobacteria, are photosynthetic and contain chlorophyll, which led to their historical classification as plants.

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects

Which one of the following statements correctly disguises Nitrosamines and Nitrobacteria?

  1. Nitrosamines is nitrifying bacterium whereas Nitrobacteria is a denitrifying bacterium

  2. Nitrosamine oxidizes ammonia to nitrite while Nitrobacteria oxidizes nitrite to nitrate

  3. Nitrosamine fixes atmospheric nitrogen into ammonia while Nitrobacteria oxidizes ammonia to nitrate

  4. Nitrosamines is responsible for amino acid synthesis while Nitrobacteria is responsible for protein synthesis
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

Rhodopseudomonas and Rhodospirillum are ______________.

  1. Purple non-sulphur bacteria

  2. Green non-sulphur bacteria

  3. Green sulphur bacteria

  4. Purple sulphur bacteria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rhodopseudomonas and Rhodospirillum are photosynthetic bacteria that belong to the group of purple non-sulphur bacteria, which use organic compounds as electron donors.

Multiple choice botany bacteria bacteria - introduction, shape and structure bacteria: types and structure bacteria; benefits and harmful effects non cellular organism : virus world of virus

State whether the following statements are true or false.
All denitrifying bacteria are heterotrophs.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Denitrifying bacteria convert nitrates in the soil to free atmospheric nitrogen, nitrogen-fixing bacteria are heterotrophs.

So, the correct option is 'True'.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

A plant capable of reducing toxic cyanide waste into non toxic form is

  1. Pseudomonas

  2. Jatropha curcas

  3. Gibberella fusarium

  4. Mirabilis Jalaplia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • There are various plants which are used in the process of bioremediation. 
  • The plants are capable of taking up the toxic constituents and accumulating them in the plant body. 
  • The plant Gibberella fusarium can take up the toxic material like cyanide. 
  • The cyanide is reduced by this plant and converted to a non-toxic form. 
  • Thus, the correct answer is option C.