Question

Nitrogen Fixing Bacteria have different speeds. Which of the following types of bacteria generally fix nitrogen at a faster rate?

a) Rhizobium
b) Azotobacter
c) Cyanobacteria
d) Bacillus

Answer 1

Rhizobium bacteria fix nitrogen at a faster rate due to their symbiotic relationship with legume plants, which is more efficient than the nitrogen fixation rates of free-living or aquatic bacteria.

Step-by-step explanation:

Among the types of nitrogen-fixing bacteria listed, Rhizobium generally fixes nitrogen at a faster rate because of their symbiotic relationship with legumes. These bacteria form specialized structures called nodules on the roots of legume plants, where nitrogen fixation occurs efficiently.

Rhizobia require a symbiotic association with the plant to fix nitrogen, using energy from the carbohydrates provided by the plant.

This association is a highly efficient way to convert atmospheric nitrogen into a form usable by plants, thus facilitating a greater rate of nitrogen fixation compared to free-living nitrogen fixers like Azotobacter and Bacillus or aquatic nitrogen fixers like cyanobacteria.