Biological Classification Question 21

21. Specialized cells for fixing atmospheric nitrogen in Nostoc are [NEET Kar. 2013]

(a) Akinetes

(c) Hormogonia

(b) Heterocysts

(d) Nodules

Show Answer

Answer : b

Hints & Solutions

(b) Heterocysts are large sized, thick-walled specialised cells which occur in terminal, intercalary or lateral position in filamentous cyanobacteria, e.g., Nostoc. They have enzyme nitrogenase and are specialised to perform biological nitrogen fixation.