1. seeds of legume
2. Clostridium
3. Rhizobium
4. leguminous root nodules
leguminous root nodules
1. bacteria
2. virus
3. Anthoceros
4. Azolla
Anthoceros
1. Aulosira
2. Anabaena
3. Scytonema
4. All of these
Anabaena
1. Algal zone
2. Bacterial zone
3. Fungal Zone
4. All of these
Algal zone
1. nitrates to nitrites
2. nitrites to molecular nitrogen
3. nitrite to nitrates
4. nitrates to ammonia
nitrites to molecular nitrogen
1. phosphorus
2. nitrogen
3. iron
4. calcium
phosphorus
1. root
2. stem
3. leaves
4. All of these
leaves
1. irreversibly absorbs O2 which inhibit N2 fixation
2. reversibly absorbs O2 which inhibit N2 fixation
3. protects plant tissues from damage by symbiotic bacteria
4. absorbs O2 at low oxygen tension and provides it to the tissue surrounding N2 fixing bacteria
reversibly absorbs O2 which inhibit N2 fixation
1. photoautotrophs
2. chemoautotrophs
3. chemoheterotrops
4. saprotrophs
chemoautotrophs
1. horsetail
2. salt marsh species
3. seleniferous plants
4. hydrophytes
salt marsh species