Question

The sites of nitrogen fixation in blue green algae are ...........

• A. vegetative cells
• B. apical cells
• C. heterocysts
• D. basal cells

Hint:

Heterocysts in blue-green algae (cyanobacteria) are the specialized cells where nitrogen fixation occurs.

Answer 1

The Correct Option is C

Step 1: Understanding nitrogen fixation in blue green algae.
In blue green algae (also known as cyanobacteria), nitrogen fixation occurs in specialized cells called heterocysts. These cells are responsible for converting atmospheric nitrogen into a form usable by the organism.
Step 2: Analyzing the options.
(A) vegetative cells: Incorrect. Vegetative cells are not involved in nitrogen fixation.
(B) apical cells: Incorrect. Apical cells are involved in the growth of the organism but not in nitrogen fixation.
(C) heterocysts: Correct. Heterocysts are specialized cells in cyanobacteria where nitrogen fixation occurs.
(D) basal cells: Incorrect. Basal cells are not specifically involved in nitrogen fixation.
Step 3: Conclusion.
The correct answer is (C) heterocysts, as these cells in cyanobacteria are responsible for nitrogen fixation.