Explain the mechanism of biological nitrogen fixation in detail

The biological nitrogen fixation is carried out by some bacte­ria, cyanobacteria and symbiotic bacteria. In symbiotic association, the bacterium provides fixed nitrogen (NH3) to the host and derives carbohydrates and other nutrients from the latter.

Biological nitrogen fixation occurs in the presence of the enzyme nitrogenase which is found inside the nitrogen fixing prokaryote. In addition to this enzyme, a source of reducing equivalents (ferredoxin (Fd) or flavodoxin in vivo), ATP and protons are required.

Explanation:

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.