Some cyanobacteria that form filamentous colonies possess heterocysts, which are
A) a means of locomotion.
B) endospores.
C) resting stages.
D) cells specialized for nitrogen fixation.
E) cells specialized for photosynthesis.

Question

Quizplus · Accepted Answer

Heterocysts are specialized cells in filamentous cyanobacteria that are capable of nitrogen fixation, a process that converts atmospheric nitrogen into a form that can be used by the organism. This process requires a low oxygen environment, which is why it occurs in specialized cells rather than in the photosynthetic cells of the filament.

Some Cyanobacteria That Form Filamentous Colonies Possess Heterocysts, Which Are