The function of leghaemoglobin is

1. to provide oxygen to leg muscles of nitrogen-fixing

2. to protect oxygen-sensitive enzymes of nitrogen fixing bacteria in the root nodules of

legumes

3. to walk to the sites where oxygen is required

4. to function when haemoglobin is not available.

The function of leghaemoglobin during biological nitrogen fixation in root nodules of legumes is to
1. convert atmospheric N₂ to NH₃
2. convert ammonia to nitrite
3. transport oxygen for activity of nitrogenase
4. protect nitrogenase from oxygen.

During nitrogen fixation, nitrite is oxidized to nitrate with the help of the bacterium:

1. Nitrosomanas
2. Pseudomonas
3. Nitrobacter
4. Thiobacillus

How many ATP molecules are required to biologically fix one molecule of nitrogen into two molecules of ammonia?
1. 4
2. 8
3. 12
4. 16