Tag: nitrogen cycle

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Questions Related to nitrogen cycle

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

Nitrifying bacteria are able to 

  1. Convert atmospheric nitrogen into soluble forms

  2. Convert ammonia to nitrate

  3. Ammonia to nitrogen

  4. Nitrate to nitrogen
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nitrification is an important process in nitrogen cycle in nature, which is brought about by nitrifying bacteria. In warm moist soils having a temperature of $30-35^0$C and neutral pH, ammonia gets oxidized to nitrite ($NO _2^-$) and then nitrate ($NO _3^-$) by the process of nitrification. 

Nitrifying bacteria like Nitrosomonas convert ammonia to nitrite and another bacterium, called as Nitrobacter converts nitrite to nitrate.

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

The common nitrogen-fixer in paddy field is _______________.

  1. Azospirillum

  2. Oscillatoria

  3. Frankia

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

The common Nitrogen fixer in the paddy field is Azospirillum. This is a soil and root bacteria. It is a nitrogen-fixing bacteria when added to the soil it multiplies and supplies 30-40Kg nitrogen per hectare per season. It also produces Indole acetic acid which helps in growth.


Hence the correct option is A.

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

The microorganisms that play an important role in maintaining the balance of nitrogen gas in the atmosphere are ________

  1. Bacteria

  2. Algae

  3. Virus

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

Rhizobium and Cynobacteria are involved in nitrogen fixation. There are many more bacteria like Nitrobacter, Nitrosomanas etc involve in maintaining the balance of nitrogen gas in the atmosphere.

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

The bacteria present in root nodules of leguminous plants that fix the atmospheric nitrogen is

  1. Rhizobium

  2. Blue-green algae

  3. Nitrifying bacteria

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

Rhizobium is a bacterium found in the root nodules of leguminous plants. It induces the formation of special structures called nodules inside which it fixes atmospheric nitrogen. It does this with the help of nitrogenase enzyme that converts of nitrogen to ammonium that is an important factor required for plant growth. In turn, the bacterium receives shelter from the plant. Thus the correct answer is option A.

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

Oxidation of Ammonia into nitrite is performed by


(a) Nitrosomonas (b) Nitrosococcus (c) Nitrobacter (d) Nitrospira

  1. a, b

  2. b, c

  3. c, d

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

Oxidation of Ammonia to nitrite is performed by two groups of bacteria. Nitrosomonas and Nitrosocossus are examples of bacterias which perform the oxidation of ammonia to nitrite.

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

Nitrifying bacteria convert the

  1. Nitrates into nitrites

  2. Nitrites into nitrates

  3. Ammonium salts into nitrates

  4. Ammonium salts into amino acids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nitrification is a process of conversion of ammonium salts to nitrites and nitrites to nitrates. The bacteria that carry out this process are called as nitrifying bacteria. Nitrosomonas, Nitrosospira, Nitrosococcus convert ammonia into nitrites. Nitrobacter, Nitrospina, Nitrococcus convert nitrites into nitrates.

Thus, the correct answer is 'Ammonium salts into nitrates.'

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

In excess, $C{O} _{2}$

  1. Accelerates growth

  2. Does not influence growth

  3. Inhibits growth

  4. Slows down growth
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Atmospheric carbon dioxide is used by plants to produced food. Due to industrialization, large amount of carbon dioxide is released in the atmosphere. This CO$ _2$ provides nutrient source to certain plants. However, excess amount of CO$ _2$ inhibits growth in plants. It inhibits nitrate assimilation in certain plants. It basically inhibits absorption of nitrogen.

Thus, the correct answer is option C.