Nitrogen Cycle (MCQ's & Short question)

 

Nitrogen cycle

MCQ’s and Short Answers:

MCQ’S

1: Which biogeochemical cycle convert nitrogen into multiple chemical forms as it circulates among  the atmosphere:

a)      Nitrogen cycle

b)      Carbonate cycle

c)      Water cycle

d)      None of the above

2: Important processes in the nitrogen cycle include :

a)      fixation, ammonification, nitrification, and denitrification.

b)      Detoxification , recycling , elimination

c)      Conversion of other substances

d)      None of the above.

3: The percentage of nitrogen in Earth's atmosphere is  :

a)      78%

b)      50%

c)      12%

d)      80%

4: Phytoplankton cannot utilize the :

a)      Phosphorus

b)     Nitrogen

c)      Both

d)      None

 

5:  Nitrogen fixation is performed by :

a)      Viruses

b)     Cyanobacteria

c)      Bacteria

d)      Fungi

6: Nitrogen that is used by plants is in the form of..

a)      Nitrogen monoxide

b)     Nitrates

c)      Oxygen

d)      Water

7: What plants do with the nitrogen they absorb?

a)      Kill other plants

b)      Use it in photosynthesis

c)      Build proteins

d)      Absorption

8: Nitrogen has a solubility in water:

a)      Low

b)      High

c)      Mediam

d)      Insoluble

9: Most of the plants cannot absorb atmospheric nitrogen instead they get it from:

a)      Soil solution & soil microorganisms

b)      From water

c)      By air

d)      None

10: some atmospheric nitrogen also fixed , when converted into oxides by:

a)      Thunderstorm & lightning

b)      Sun light

c)      Smog

d)      None

 

11: Nitrogen is lost from local ecosystem by :

a)      Volatilization of organic waste

b)      Thunderstorm

c)      Industrial smoke

d)      Both a & b

12: The total soil nitrogen pool is highly dependent on :

a)      Soil microorganisms

b)      Sun light

c)      Air

d)      All of these

13: Excess nitrogen is said to cause:

a)      Gas disease in fishes

b)      Kidney disease

c)      High respiratory rate

d)      No effect

14: Some researches show that extractives from marsh and peat materials contain relatively small amounts of :

a)      Metals

b)      Plastics

c)      Nitrogen

d)      Phosphorus

15: The oxygen is more soluble than nitrogen, the air that is dissolved in the water contain 34.91% oxygen and ____% nitrogen.

a)      65.5%

b)      90%

c)      12%

d)      0%

 

 

 

                   SHORT ANSWERS

1 Q: Define Nitrogen cycle?

Ans: Nitrogen is the most abundant gas in the atmosphere , The functioning ecosystems is limited by the availability of this element, to fulfill this requirement the nitrogen move through the atmosphere to plants and soil and to other animals , This movement of nitrogen is called nitrogen cycle.

 

2 Q: Which microorganisms are involve in the nitrogen cycle?

Ans: The microorganisms are involve at key steps in the cycling of nitrogen ,

          1: Symbiotic nodule forming bacteria in the roots of agricultural legumes.

         2: Symbiotic nodule forming bacteria on the root of non-leguminus plants

         3: Symbiotic cyanobacteria

         4: Free living bacteria  

3 Q: name the different steps of nitrogen cycle?

Ans:  The steps of nitrogen cycle

  1: Nitrogen fixation

  2: Ammonification

  3: nitrification

4: Assimilation

  5: Di-nitrification

 

4 Q: Define Ammonification?

Ans: Ammonifying( bacteria involve in the ammonification) bacteria and fungi , which release ammonium ions by breaking down decaying organic matter in soil.   

5 Q:  Define nitrification?

Ans: Nitrifying bacteria (which involve in the nitrification), Chemoautotrophs that convert soil ammonium to nitrite and nitrite to nitrate.

 

6 Q:  What are the processes which are involve in the nitrogen fixation other than microorganisms?

Ans: Apart from the activities of microorganisms, some atmospheric nitrogen is also c  fixed during thunderstorms when nitrogen is converted to oxides by lightening and washed from the atmosphere by rain.

 

7 Q:  How nitrogen lost from ecosystem?

Ans: Nitrogen is lost from the local ecosystems by the volatilization of organic waste ,This amount can become major during bushfire and from stock piles of animal excreta accumulated in intensive live-stock operations.

8 Q:  In which form the nitrogen present in the atmosphere?

Ans: Nitrogen present in atmosphere in the form of  Nitrate and nitrites.

 

9 Q: Draw the nitrogen cycle?

Ans:               

                                

10 Q: What is the percentage of nitrogen in the atmosphere of Earth?

Ans: The percentage of nitrogen in the atmosphere of Earth is 78%.