Tag: bio-geo chemical cycles in nature

Questions Related to bio-geo chemical cycles in nature

What is natural sources of CO?

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

  1. solid waste disposal

  2. Volcanic eruption and forest fire

  3. Motor vehicles

  4. Fuel combustion

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Correct Option: B

One molecule of CFCs contain 15000 molecules of

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

  1. $CO _{2}$

  2. $CO$

  3. HCFCs

  4. CH4

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Correct Option: A

Proportion of CO consumption consists of basic components:

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

  1. The leaf boundary layer

  2. The stomata

  3. Radiation exchange

  4. All of Above

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Correct Option: D

Carbon dioxide constitutes about 0.03% of the atmosphere

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

  1. By volume

  2. By weight

  3. By mass

  4. None of these

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Correct Option: A
Explanation:

The air in our atmosphere is composed of molecules of different gases. The most common gases nitrogen  (78%), oxygen (about 21%), argon (almost 1%) and carbon dioxide (0.03%). Other molecules are present in  the atmosphere as well, but in very small quantities. Composition of air is measured in percent by volume,  at sea level at 15C and 101325 Pa.

Phtotochemical phase does not includes ________________.

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

  1. Fixation of ${CO} _{2}$

  2. Release of ${O} _{2}$

  3. Photolysis of water

  4. Formation of ATP and NADPH

Show answer
Correct Option: A
Explanation:

Photochemical phase includes photolysis of water and production of assimilatory power (ATP and NADPH). It liberates O2  during photolysis of water. 

The photochemical phase do not include fixation of CO2.

Chemical reactions triggered by ___________ transforms the organic material into hydrocarbons.

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

  1. solar energy

  2. hydroelectric

  3. elevated temperatures

  4. decomposition

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Correct Option: C

Reaction carried out by $N _2$ fixing microbes include
$2NH _3 + 3O _2 \rightarrow 2NO _2^- + 2H^+ + 2H _2O$            (i)
$2NO _2^- + O _2 \rightarrow 2NO _3^-$                                       (ii)
Which of the following statements about these equations is not true?

zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

  1. Step (i) is carried out by Nitrosomonas or Nitrosococcus

  2. Step (ii) is carried out by Nitrobacter

  3. Both step (i) and (ii) can be called nitrification.

  4. Bacteria carrying out these steps are usually photoautotrophs.

Show answer
Correct Option: D
Explanation:
Phototrophic bacteria are a group of bacteria, whose energy for growth is derived from sunlight and their source of carbon comes from carbon dioxide or organic carbon.
So, the correct option is 'Bacteria carrying out these steps are usually photoautotrophs'.

A farmer adds Azotobacter culture to soil before sowing maize. Which mineral element will be replenished by doing so?

zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

  1. N

  2. P

  3. K

  4. S

Show answer
Correct Option: A
Explanation:
Azotobacter is a free living bacteria in the soil. It helps some cereal crops like maize (Zea mays) in nitrogen fixation. The farmer adds Azotobacter culture to the maize field for enhancing the nitrogen element in the soil by the process of biological nitrogen-fixation. 
Thus, the correct answer is 'N.'

Which of the following is a non-symbiotic nitrogen fixing prokaryote?

zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

  1. Azotobacter

  2. Clostridium

  3. Beijerinckia

  4. All of these

Show answer
Correct Option: D
Explanation:

Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (non-symbiotic) bacteria, includes the cyanobacteria (or blue-green algae), Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium. 

Thus, the correct answers is 'All of these.'

Which of the following is a free living aerobic nitrogen fixing bacterium present in the soil?

zoology bio-geo chemical cycles in nature nitrogen cycle biogeochemical cycles - gaseous nutrient cycles

  1. Nitrosomonas

  2. Rhizobium

  3. Azotobacter

  4. Pseudomonas

Show answer
Correct Option: C
Explanation:

Azotobacter and Beijerinckia  are aerobic free living saprophytic nitrogen fixing bacteria, while Clostridium is anaerobic free living saprotrophic nitrogen fixing bacterium.