Tag: carbon cycle

Questions Related to carbon cycle

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.

True or False:
Burning of fossil fuels liberate oxygen.

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

  1. True

  2. False

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Correct Option: A

Which gas is likely to be reduced in the atmosphere by deforestation?

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

  1. Carbon dioxide

  2. Nitrogen

  3. Oxygen

  4. Sulphur dioxide

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Correct Option: C

The ozone at ground level is primarily from__________ precursors

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

  1. Fossil fuel

  2. $CFC _{S}$

  3. Oxygen

  4. Methane

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Correct Option: A

Phosphorous, is needed for the

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

  1. Growth

  2. Decomposition

  3. Photosynthesis

  4. Eutrophication

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Correct Option: C

Which chemical was used as a foam blowing agents?

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

  1. Cl

  2. CFCs

  3. PAN

  4. Feron 11

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Correct Option: B

What is concentration of $O _{2}$ in atmosphere?

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

  1. 12%

  2. 20.90%

  3. 21%

  4. 22%

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Correct Option: B