Ciliates: nuclear divisions during reproduction During binary fission, the number of nuclear divisions is how compared with conjugation?

Introduction:
Ciliates possess nuclear dimorphism: a micronucleus (germline) and a macronucleus (somatic). Understanding how these nuclei divide in different processes—binary fission versus conjugation—clarifies eukaryotic cell cycles and sexual recombination in protozoa.

Given Data / Assumptions:

• Binary fission: asexual division producing two cells.
• Conjugation: sexual process with exchange and reorganization of micronuclei.
• We compare the counts of nuclear divisions involved.

Concept / Approach:
In binary fission, the micronucleus typically undergoes one mitotic division and the macronucleus divides by amitosis. In conjugation, the micronucleus undergoes multiple divisions (meiosis producing haploid nuclei, followed by additional mitoses and fusions) before a new macronucleus develops. Therefore, the total number of nuclear divisions is greater in conjugation than in simple fission.

Step-by-Step Solution:
Recall: binary fission → one mitosis of micronucleus; macronucleus splits amitotically. Recall: conjugation → micronuclear meiosis, selection of pronuclei, exchange, fusion (syngamy), post-zygotic mitoses, and macronuclear differentiation. Count events: conjugation includes several division steps versus a single mitosis in fission. Conclude: binary fission has fewer nuclear divisions.

Verification / Alternative check:
Classic Paramecium life-cycle diagrams show three or more sequential micronuclear divisions during conjugation contrasted with one during binary fission, confirming the inequality.

Why Other Options Are Wrong:
Greater than conjugation – reversed.

Equal to conjugation – contradicted by meiosis and subsequent mitoses in conjugation.

None/Varies unpredictably – the patterns are well characterized and reproducible.

Common Pitfalls:
Counting macronuclear amitosis as multiple mitoses; it is not equivalent to the series of meiotic/mitotic events in conjugation.

Final Answer:
Lesser than conjugation.