NEET BIOLOGY

Detailed explanation-1: -Nitrogen fixation is carried out naturally in soil by microorganisms termed diazotrophs that include bacteria, such as Azotobacter, and archaea.

Detailed explanation-2: -The Rhizobium or Bradyrhizobium bacteria colonize the host plant’s root system and cause the roots to form nodules to house the bacteria (Figure 4). The bacteria then begin to fix the nitrogen required by the plant.

Detailed explanation-3: -Atmospheric nitrogen (N2)-fixing bacteria inhabit both plant tissues (e.g., nodules, roots) and soil-root rhizosphere interface and can, consequently, supply significant N amounts for plant growth.

Detailed explanation-4: -Rhizobia. Rhizobia are nitrogen-fixing bacteria classified and characterized by different systems. Beijerinck was able to isolate and cultivate a microorganism, named Bacillus radiocicola, from the nodules of legumes in 1888.

Detailed explanation-5: -The role of nitrogen-fixing bacteria is to supply plants with the vital nutrient that they cannot obtain from the air themselves. Nitrogen-fixing microorganisms do what crops can’t – get assimilative N for them. Bacteria take it from the air as a gas and release it to the soil, primarily as ammonia.