Tag: zoology

Questions Related to zoology

Which bacteria is responsible to fix nitrogen in leguminous plants?

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Azotobacter

  2. Rhizobium

  3. Clostridium

  4. Saccharomycese

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Correct Option: B
Explanation:

Some bacteria maintain the soil fertility and others enhance it. The fertility of the soil is proportional to the nitrogen content. Nitrogen is an important ingredient in the structure and function of the living beings. Nitrogen-fixing bacteria like Azotobacter, Clostridium live free in the soil and fix atmospheric nitrogen. Rhizobium like bacteria live symbiotically with root systems of leguminous plants and fix from the atmospheric nitrogen. Therefore, the correct answer is option B.

The microbial biofertilizers which can act both symbiotically and non-symbiotically to increases soil fertility are

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Azotobacter

  2. Rhizobium

  3. Clostridium

  4. `Nostoc and Anabaena

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Correct Option: A
Explanation:

Azotobacter can act both as symbiotically and non symbiotically to increase soil fertility. It Infuse the soil with antibiotic pesticides and inhabit the spread of soil borne diseases like pythium and phytophthora.

Free living nitrogen fixing biofertilizer is

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Glomus

  2. Rhizobium

  3. Azotobacter

  4. Pseudomonas

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Correct Option: C
Explanation:

Azotobacter is a heterotrophic free living nitrogen fixing bacteria present in alkaline and neutral soils.

Some of the nutrient cycles are labelled as below. Sulphur
cycle (A), phosphorus cycle (B), carbon cycle (C) and
nitrogen cycle (D)
Of these, the sedimentary cycle is represented by

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. (A) only

  2. (B) only

  3. (C) only

  4. (A) and (B) only

  5. (C) and (D) only

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Correct Option: D

Burning of fossil fuels affects

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Nitrogen cycle

  2. Carbon cycle

  3. Phosphorus cycle

  4. Water cycle

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Correct Option: B

The bacterium nitrobacter converts

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Nitrogen to nitrite

  2. Ammonia to nitrite

  3. Nitrite to nitrate

  4. Nitrate to nitrite

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Correct Option: C
Explanation:

Nitrification is a two step process of converting ammonia into nitrites and nitrites into nitrates. Bacteria converting ammonia into nitrites includes Nitrosomonas. Bacteria converting nitrites to nitrates includes Nitrobacter.

Thus, the correct answer is 'Nitrite to nitrate.'

Nitrogen fixing bacteria- anabaena - are found in the plant ______

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Azolla leaves

  2. Cycas corolloid roots

  3. Anthoceros body

  4. All of these

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Correct Option: D
Explanation:
Anabaena are the one type of cyanobacteria, present in the leaves of Azolla, Corolloid roots of Cycas, Anthoceros body. They perform symbiotic Nitrogen fixation.
So the correct option is 'All of these'.

The biological process by which carbon is returned to its reservoir is

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. photosynthesis

  2. denitrification

  3. carbon fixation

  4. cellular respiration

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Correct Option: D
Explanation:
A. Photosynthesis is the process in which plants prepare their own food using carbon dioxide and water which are converted into glucose in the presence of sunlight along with the release of oxygen.
B. Denitrification is a process of reduction of nitrate into molecular nitrogen by denitrifying bacteria.
C. Carbon fixation is the reduction and incorporation of inorganic carbon into organic compounds.
D. Cellular respiration is a metabolic reaction in which energy is released from the breakdown of complex substances. Oxygen is used in respiration and carbon dioxide is released. Hence, carbon is returned to its reservoir through cellular respiration.
So, the correct answer is 'cellular respiration'.

Which one of the following is a wrong statement ? 

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Phosphorus is a constituent of cell membranes, certain nucleic acids and all proteins

  2. Nitrosomonas and Nitrobacter are chemoautotrophs

  3. Anabaena and Nostoc are capable of fixing nitrogen in free living state

  4. Root nodule forming nitrogen fixers live as aerobes under free living conditions

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Correct Option: A
Explanation:
A. Phosphorus is constituent of cell membranes in the form of phospholipids and also present in nucleic acids as phosphate in the sugar-phosphate backbone.
B. Nitrosomonas and Nitrobacter are nitrifying bacteria. These bacteria derive energy by oxidizing inorganic nitrogenous compounds. Hence, they are called chemoautotrophs.
C. Anabaena and Nostoc are cyanobacteria (also known as blue-green algae). They are free-living bacteria and can fix nitrogen because they have specialized cells called heterocysts with the help of which they can fix atmospheric nitrogen.
D. Root nodule forming nitrogen-fixing microbes live freely in the soil as aerobes. They form a symbiotic association with the roots of plants when some chemicals or factors are released by the plants. For example, Rhizobium.
Hence, statement A is incorrect.
So, the correct answer is 'Phosphorus is a constituent of cell membranes, certain nucleic acids, and all proteins'.

The bacteria ______ supply natural manure to paddy fields.

zoology bio-geo chemical cycles in nature nutrient cycles- flow of substances carbon cycle biogeochemical cycles - gaseous

  1. Azolla

  2. Anabaena

  3. Azotobacter

  4. Nostoc

Show answer
Correct Option: A
Explanation:
The bacteria Azolla supplies natural manure to the paddy fields. Azolla is a gliding pteridophyte, which contains as endosymbiont the nitrogen-settling cyanobacterium Anabaena azollae (Nostocaceae family). 
Generally developed in the Asian districts, Azolla is either consolidated into the dirt before rice transplanting or developed as a double product alongside rice. 
So, the correct answer is A.