As the members of a given generation age, their instinct of social conservation becomes stronger, which inevitably and necessarily brings them into conflict with the normal attribute of youthâinnovation. Other important theorists of the 19th century were John Stuart Mill and Wilhelm Dilthey.
Plants require more than just water and sunlight to grow. They also require many nutrients found in the soil. One of the most important nutrients required for plant growth is nitrogen. Nitrogen is used to build plant proteins and nucleic acids, including DNA.
The bacteria fix nitrogen by converting it to ammonia and nitrates which the plant can absorb and use to build its nitrogen containing molecules such as amino and nucleic acids. In return it offers some of its own sugars to the bacteria to cover their needs. It's a trade off between biologically usable nitrogen and sugar.