AP BIOLOGY

Detailed explanation-1: -Prokaryotes play several roles in the nitrogen cycle. Nitrogen-fixing bacteria in the soil and within the root nodules of some plants convert nitrogen gas in the atmosphere to ammonia.

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: -The bacteria that we are talking about are called nitrosomonas and nitrobacter. Nitrobacter turns nitrites into nitrates; nitrosomonas transform ammonia to nitrites.

Detailed explanation-4: -Rhizobium: Rhizobium is the nitrogen fixing bacteria which are present in the root nodules of the leguminous plants.

Detailed explanation-5: -Nitrosomonas bacteria first convert nitrogen gas to nitrite (NO2-) and subsequently nitrobacter convert nitrite to nitrate (NO3-), a plant nutrient. Plants absorb ammonium and nitrate during the assimilation process, after which they are converted into nitrogen-containing organic molecules, such as amino acids and DNA.