Answer:
Cyanobacteria, Anabaena and Azotobactor are called Nitrogen fixing bacteria. These bacteria change the nitrogen in the atmosphere into a form that is used by the plants to make proteins. Plants take nitrogen in the form of nitrates. The atmospheric nitrogen is first converted into ammonia after that ammonia is converted into nitrates and this nitrates use by the plants to make proteins.
In regards to this question, there are no specific options provided to choose from. So i will try and answer as perfectly as possible from my knowledge. Hope it will be of help to you. Optical telescopes tend to have a magnifying lens located near the large opening at the opposite end of the eye pice through which a person looks.