Nitrogen Cycle

Q. Nitrite reductase enzyme is used to convert

1. nitrate into nitrite ion
2. nitrogen of atmosphere into ammonia
3. ammonia into nitrates
4. nitrite to ammonia

Q. Match the following columns related to nitrogen cycle
$\begin{array}{cc}\text{Column - I}& \text{Column - II}\\ \text{A. Nitrogen fixation}& \text{1.Conversion of}N{H}_3\text{to}N{O}_3^{-}\\ \text{B. Nitrogen assimilation}& \text{2.Conversion of}N{O}_3^{-}\text{or}N{H}_3\text{to organic nitrogen}\\ \text{C. Ammonification}& \text{3.Conversion of}N{O}_3^{-}\text{to atmospheric nitrogen}\\ \text{D. Nitrification}& \text{4.Conversion of}{N}_{2}toN{O}_3^{-}\text{or}N{H}_3\\ \text{E. Denitrification}& \text{5.Conversion of organic nitrogen to}N{H}_3\end{array}$

1. A - 1, B - 2, C - 3, D - 4, E - 5

2. A - 4, B - 2, C - 5, D - 1, E - 3

3. A - 5, B - 4, C - 3, D - 2, E - 1

4. A - 4, B - 2, C - 5, D - 3, E - 1

Q. Anabaena, Nostoc and Oscillatoria exhibit certain common characteristics. Choose the correct option.

Q.

Which of the following is a bacterium involved in denitrification?

1. Azotobacter

2. Nitrosomonas

3. Pseudomonas

4. Nitrobacter