Question

Which of the following cannot fix nitrogen?
(a) Nostoc (b) Azotobacter
(c) Spirogyra (d) Anabaena

Answer 1

Answer:

d is the correct answer...

Answer 2

Nitrogen fixation:

• Option “C” is correct i.e. Spirogyra.

• The spirogyra is not a nitrogen-fixing bacteria.

• While azotobacter, anaebena, and nostoc are nitrogen-fixing bacteria.

•  Spirogyra is green algae which do photosynthesis. It cannot fix nitrogen

• Spirogyra is filamentous chlorophyte green algae of the order Zygnematales, baptized for the helical or spiral prearrangement of the chloroplasts that is representative of the genus. It is usually found in freshwater habitats.

Hope it helped...