Question

Select the mismatched pair

• A. Symbiotic bacteria - Rhizobium, Frankia
• B. Symbiotic cyanobacteria - Frankia, Aulosira
• C. Free-living bacteria - Beijerinckia, Azotobacter
• D. None of these

Answer 1

The correct option is B Symbiotic cyanobacteria - Frankia, Aulosira

Symbiotic bacteria are bacteria living in symbiosis with another organism or each other. For example Rhizobium, Frankia. Cyanobacteria are a large group of photosynthetic prokaryotes of enormous environmental importance, being responsible for a large proportion of N${}_2$ fixation. They form symbiotic associations with a wide range of eukaryotic hosts including plants, fungi, sponges, and protists.

Free-living (non-symbiotic) bacteria include the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium; and symbiotic bacteria includes Rhizobium, associated with leguminous plants.

Thus, the mismatched pair is 'Symbiotic cyanobacteria - Frankia, Aulosira.'