Comparing locomotory organelles: Relative to ciliated cells, the number of motility structures on flagellated cells is usually…

Introduction: Protozoan locomotion can be mediated by flagella or cilia. Knowing how many organelles are typically present on a cell helps distinguish flagellates from ciliates in both exams and microscopy labs.

Given Data / Assumptions:

• Ciliates commonly bear numerous short cilia arranged in rows or fields.
• Flagellates usually possess one to a few long flagella.
• We compare relative numbers, not absolute lengths.

Concept / Approach: Cilia are abundant—often hundreds per cell—coordinated for effective power/recovery strokes. Flagella are few (1–8 is typical in protists like Giardia, Trichomonas, Euglena). Therefore flagellated cells have fewer motility structures than ciliated cells.

Step-by-Step Solution: Identify the organelle type: flagellum versus cilium. Recall the characteristic counts: few flagella versus many cilia. Apply the comparison: “lesser than.” Choose the corresponding option.

Verification / Alternative check: Light microscopy of Paramecium (ciliate) shows dense ciliation, while Giardia or Trichomonas show a small set of flagella, confirming the numerical contrast.

Why Other Options Are Wrong: Greater/equal – contradicted by standard morphology.

None/Variable hundreds – mischaracterizes flagellates; hundreds per cell describes ciliates.

Common Pitfalls: Confusing organelle length (flagella are longer) with number (which is fewer). Exams often test this distinction.

Final Answer: Lesser than ciliated cells.