Asexual reproduction in protozoa — what is the most common mode?

Introduction:
Protozoa replicate rapidly through asexual means in many environments. Knowing the predominant asexual mechanism aids in understanding growth dynamics and population surges.

Given Data / Assumptions:

• Options mix sexual and asexual processes.
• We must identify the common asexual method.

Concept / Approach:
Binary fission is mitotic division yielding two daughter cells. It is widespread among protozoa and underlies rapid clonal expansion. Conjugation is sexual; gametangial contact is a fungal concept; “binary fusion” is not standard protozoan terminology.

Step-by-Step Solution:

Verification / Alternative check:
Most lab cultures of amoebae, flagellates, and ciliates expand mainly via binary fission under favorable conditions.

Why Other Options Are Wrong:

• Conjugation: recombination, not asexual multiplication.
• Gametangial contact: not protozoan standard.
• Binary fusion: lacks standard definition in protozoology.

Common Pitfalls:
Confusing frequency of asexual vs sexual events; asexual cycles dominate daily growth.

Final Answer:
Binary fission