Azolla, used as a biofertilizer for rice cultivation, has a symbiotic relationship with

examrobotsa's picture

Submitted by examrobotsa on

Q: 43 (IES/2002)
Azolla, used as a biofertilizer for rice cultivation, has a symbiotic relationship with

question_subject: 

Science

question_exam: 

IES

stats: 

0,51,161,114,41,6,51

keywords: 

{'azotobacter': [0, 0, 2, 0], 'azospirillum': [0, 0, 2, 1], 'azolla': [2, 0, 2, 0], 'biofertilizer': [1, 0, 0, 0], 'rice cultivation': [0, 0, 1, 1], 'symbiotic relationship': [0, 0, 0, 2], 'anabaena': [1, 0, 2, 0], 'aulosira': [0, 0, 1, 0]}

Azolla is a small aquatic fern that is commonly used as a biofertilizer for rice cultivation. It has a unique symbiotic relationship with a group of nitrogen-fixing cyanobacteria known as Anabaena. Nitrogen fixation is the process by which certain bacteria convert atmospheric nitrogen into a form that plants can use.

Option 1, Azotobacter, is not the correct answer. Although Azotobacter is a nitrogen-fixing bacterium, it does not have a symbiotic relationship with Azolla.

Option 2, Azospirillum, is also not the correct answer. Azospirillum is another type of nitrogen-fixing bacterium, but it does not form a symbiotic relationship with Azolla.

Option 3, Aulosira, is not the correct answer either. Aulosira is a filamentous cyanobacterium, but it does not have a symbiotic relationship with Azolla.

Therefore, the correct answer is option 4, Anabaena. Anabaena forms symbiotic associations with Azolla, specifically in specialized cavities known as "hairs" on the underside of Azolla`s leaves. Inside these cavities, Anabaena perform nitrogen fixation, providing a natural source of nitrogen to the Azolla plants