Question

The seeds of leguminous plants are a source of protien .Nitrogen fixing bacteria live in the roots of such plants

Answer 1

There is a mutualistic relationship between the plant and the bacteria. The plant provide carbohydrates, which act as an energy source for the bacteria and the bacteria absorb nitrogen and convert it into useful nitrogenous compounds. The plant uses these compounds (e.g. ammonia) to make proteins. (Plants are unable to perform nitrogen fixing by themselves).