Question

Certain organisms possess specialized structures called heterocysts that help in fixing one of the gases from the atmosphere using the enzyme nitrogenase. Which group of organisms possess heterocysts?

• A. Dinoflagellates
• B. Euglenoid
• C. Cyanobacteria
• D. Archaebacteria

Answer 1

The correct option is C Cyanobacteria

Cyanobacteria are the blue-green algae which have the ability of nitrogen fixation. The nitrogenase enzyme is present in the heterocyst of this organism. The heterocysts are the specialised cells other than the vegetative cells. The nitrogenase enzyme helps in the nitrogen fixation.

Thus, the correct answer is option C.