Denitrification

Q. Anaerobic nitrogen fixing bacterium is

1. Rhodospirillum
2. Azotobacter
3. Chlorobium
4. nostoc

Q. The process of conversion of $N{O}_3\to N{H}_3\to N_2$ is called _______ and is done by

1. denitrification, Pseudomonas
2. nitrate assimilation, Nitrogenase
3. nitrification, Nitrosomonas
4. ammonification, Bacillus

Q.

The given equation refers to N₂ + 8e^– + 8H⁺ + 16ATP → 2NH₃ + H₂ + 16ADP + 16P_i

1. Nitrification

2. Denitrification

3. Ammonification

4. Nitrogen Fixation

Q. What does A and B represent in the given diagram

1. nitrification (A), denitrification (B)
2. denitrification (A), ammonification (B)
3. denitrification(A), nitrogen fixation (B)
4. ammonification (A), denitrification (B)

Q. In $N_2$ cycle, Pseudomonas denitrificans helps in

1. oxidising ammonia to nitrite
2. none of these
3. nitrogen fixation
4. producing elemental nitrogen

Q. Thiobacillus is a group of bacteria helpful in carrying out:

1. Denitrification
2. Nitrogen fixation
3. Chemoautotrophic fixation
4. Nitrification

Q.

Name an agent which causes denitrification?

Q.

Identify the correct sequence of denitrification

1. N₂ - NO - NO₂^- - NO₃^-

2. N₂ - NO₂^- - NO₃^- - NO₄^-

3. NO₃^- - NO₂^- - NO - NO₂

4. N₃^- - NO₂^- - NO - NH₄⁺

Q. Thiobacillus and Pseudomonas help in maintaining equilibrium of nitrogen in atmosphere.

1. True

2. False

Q. Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation?

1. Nitrogenase is insensitive to oxygen.
2. Nodules act as sites nitrogen fixation.
3. Leghaemoglobin scavenges oxygen and is pinkish in colour.
4. The enzyme nitrogenase catalyses the conversion of atmospheric $N_2$ to $N{H}_3$.

Q. Some bacteria such as ‘X’ and ‘Y’ occur in soil which reduce nitrate to nitrogen by the process of ‘Z’. Identify ‘X’, ‘Y’ and ‘Z’.

1. ‘X’-Nitrobacter, ‘Y’-Nitrococcus, ‘Z’-Ammonification
2. ‘X’-Nitrosomonas, ‘Y’-Thiobacillus, ‘Z’-Ammonification
3. ‘X’-Pseudomonas, ‘Y’-Thiobacillus, ‘Z’-Nitrification
4. ‘X’-Pseudomonas, ‘Y’-Thiobacillus, ‘Z’- Denitrification

Q. Thiobacillus is a group of bacteria helpful in carrying out :

1. Chemoautotrophic fixation
2. Nitrification
3. Denitrification
4. Nitrogen fixation

Q.

Identify A-D

Q. In $N_2$ cycle, Pseudomonas denitrificans helps in

1. nitrogen fixation
2. producing elemental nitrogen
3. oxidising ammonia to nitrite
4. none of these

Q. Thiobacillus and Pseudomonas help in maintaining equilibrium of nitrogen in atmosphere.

1. True
2. False

Q.

Identify the correct sequence of denitrification

1. $N_2\to NO\to N{O}_2^{}\to N{O}_3^{-}$

2. $N_2\to N{O}_2^{}\to N{O}_3^{-}\to N{O}_4^{-}$

3. $N{O}_3^{-}\to N{O}_2^{}\to NO\to N{H}_4^{+}$

4. $N{O}_3^{-}\to N{O}_2^{-}\to NO\to N{O}_2$