Answer:
The roots organ is genereally placed under the soil and may undero variious modifications. The roots are present in plant that help them to absorb water and nutrient from the soil.
Some plant roots contains the bacteria that helps in the conversion of nitrogen into ammonium ions. The plants changes the roots because the rhizobium present in plant roots helps in the conversion of nitrogen so that it can be used by the plants. The Rhizobium produces ammonium (NH4+) ions.
