Name' the most crucial enzyme found in root nodules for N2 fixation? Does it require a special pink coloured pigment for its functioning? Elaborate.

Name the special genes found in Rhizobium for N_2 fixation.

Read the following paragraph and answer the questions based on it. Rhizobium living in root nodules supply nitrates, nitrites and amino acids to that plant and in exchange get energy in the form of carbohydrates from it. Such a mutually beneficial relationship is called symbiosis. Rhizobium produce nitrogenous compounds from atmospheric nitrogen. However, for this process of nitrogen fixation, they need leguminous plants like beans, sweet pea, soyabean, etc. as ‘host’. Beans and pulses are rich in proteins due to the nitrogenous compounds made available by Rhizobium. After harvesting a leguminous crop, the left-over roots and other plant parts are deliberately dumped in farm soil to maintain its bacterial population. The use of Rhizobium has helped to reduce the use of chemical fertilizers and thereby their adverse effects. It has also helped to reduce expenses on fertilizers and thus works to the benefit of farmers. Why does left over roots and other plant parts are deliberately dumped in farm soil after harvesting a leguminous crop?

Read the following paragraph and answer the questions based on it. Rhizobium produce nitrogenous compounds from atmospheric nitrogen. However, for this process of nitrogen fixation, they need leguminous plants like beans, sweet pea, soyabean, etc. as ‘host’. Rhizobium living in root nodules supply nitrates, nitrites and amino acids to that plant and in exchange get energy in the form of carbohydrates from it. Such a mutually beneficial relationship is called symbiosis. Beans and pulses are rich in proteins due to the nitrogenous compounds made available by Rhizobium. After harvesting a leguminous crop, the left-over roots and other plant parts are deliberately dumped in farm soil to maintain its bacterial population. The use of Rhizobium has helped to reduce the use of chemical fertilizers and thereby their adverse effects. It has also helped to reduce expenses on fertilizers and thus works to the benefit of farmers. How does Rhizobium help to save money of the farmers?