Nitrogen Fixation

Q.

The first stable product of fixation of atmospheric nitrogen in leguminous plants is:

1. Ammonia

2. Glutamate

3. $N{O}_2^{-}$

4. $N{O}_3^{-}$

Q. In nitrogen fixation, nitrogen is converted into

1. NO₂ or NO or N₂

2. N₂ or Amino acid or NH ₄⁺

3. NO₂ or NO₃ or NH₃

4. N₂ or NH₃ or NH₄⁺

Q. Why are cyanobacteria considered useful in paddy fields?

Q. Is nitrogen fixation and nitrification same.

Q. The source of energy for non-biological nitrogen fixation is

1. by ionizing events such as lightning and effect of cosmic rays
2. ferredoxin enzyme and nitrogenase
3. by reduction of proteins to ammonia
4. by oxidation of ammonia to protein

Q. How many of the following organisms cannot fix the atmospheric nitrogen in a free living condition?
Frankia, Anabaena, Rhodospirillum, Beijernickia, Rhizobium, Azotobacter, Nostoc

1. 3
2. 2
3. 5
4. 4

Q. $N_2+8e^{-}+8H^{+}+16ATP\to 2N{H}_3+H_2+16ADP+16Pi$
The above equation summarizes which among the following process?

1. Reductive amination
2. Nitrification
3. Nitrogen fixation
4. Denitrification

Q. Organic nitrogen compounds is/are

1. Nitrogen that is converted into NH₄⁺

2. Amino acids, proteins, enzymes, nucleic acids hormones and pigments

3. Nitrogen that is converted into nitrates and ammonia

4. Nitrogen present in the atmosphere

Q. A farmer adds Azotobacter culture to soil before sowing maize. Which mineral element is being replenished?

Q. Microbes which act as biofertilisers are

Q. Knot like bodies known as "nodules" found in the root of groundnut plant are produced by :

1. Azospirillum
2. Pseudomonas
3. Rhizobium
4. Azotobacter

Q. Heterocysts are found in certain

1. Viruses
2. Bacteria
3. Cyanobacteria
4. Mycoplasma

Q. During biological nitrogen fixation by bacteria which one of the following elements produces toxic effect?

1. Copper
2. Aluminium
3. Tungsten
4. Arsenic

Q. In nitrogen fixation, nitrogen is converted into

1. $N{O}_2,NOor{N}_2$
2. $N{O}_2,N{O}_3^{-}orN{H}_3$
3. $N_2,N{H}_{3}orN{H}_4^{+}$
4. $N_2,AminoacidsorN{H}_4^{+}$

Q. Very Short Answer Type :
In the root nodules of leguminous plants, what is the role of nitrogenase and leghaemoglobin ?

Q. Which of the following is a nitrogen fixing organism?

1. Aspergillus
2. Rhizobium
3. Both A and B
4. None of the above

Q. Which one is a biofertilizer?

1. Mycorrhiza
2. Nitrogen fixing bacteria
3. Nitrogen fixing cyanobacteria
4. All the above

Q. Read the below given conversion.

N${}_2$+8e${}^{–}$+8H${}^{+}$+16ATP $\to$ A+B+16ADP +16Pi

Identify A and B and select the correct option.

1. A – 2NH${}_3$, B – O${}_2$
2. A – NO${}_3^{-}$ , B – H${}_2$O
3. A – 2NH${}_3$, B – H${}_2$
4. A – NO${}_3^{-}$ , B – H${}_2$O

Q. The association of Nitrogen fixing bacteria (nodule bacteria) with leguminous roots is known as

1. Saprophytism
2. Epiphytism
3. Symbiosis
4. Parasitism

Q. Select the mismatch

1. Rhodospirillum – Mycorrhiza
2. Frankia – Alnus
3. Anabaena – Nitrogen fixer
4. Rhizobium – Alfalfa

Q. Which of the following is a symbiotic nitrogen fixer?

1. Azotobacter
2. Frankia
3. Azolla
4. Glomus

Q. Which of the following crops would enrich the soil with nitrogen?

1. Apple
2. Beans
3. Paddy
4. Potato

Q. In nitrogen fixation, nitrogen is converted into

1. $N_2,AminoacidsorN{H}_4^{+}$
2. $N{O}_2,N{O}_3^{-}orN{H}_3$
3. $N{O}_2,NOor{N}_2$
4. $N_2,N{H}_{3}orN{H}_4^{+}$

Q. Out of the following elements, which one is absorbed from the soil as mineral nutrition?

1. Oxygen
2. Carbon
3. Hydrogen
4. Nitrogen

Q. Root nodules are seen in the plants belonging to the family ________.

1. Fabaceae
2. Solanaceae
3. Liliaceae
4. Asteraceae

Q. the process of nitrogen fixation by bacteria does not take place in the presence of elemental form of oxygen . why ?

Q. Root nodules which are present in plants are meant for fertilizers and are found in

1. Certain leguminous plants
2. Casuarina
3. Both A and B
4. None of the above

Q.

If by radiation all nitrogenase enzyme are inactivated, then there will be no

1. Conversion from ammonium to nitrate in soil

2. Fixation of nitrogen in legumes

3. Fixation of atmospheric nitrogen

4. Conversion from nitrate to nitrite in legumes

Q. During symbiotic biological nitrogen fixation. The recognition of Rhizobia host interaction involves two classes of molecules there are _______________.

1. Lectins and Alkaloids
2. Lectins an lipids
3. Lectins and Polysaccharides
4. Flavonoids and Oligosaccharides

Q. Select the mismatch

1. Rhizobium – Alfalfa
2. Rhodospirillum – Mycorrhiza
3. Frankia – Alnus
4. Anabaena – Nitrogen fixer