Cilia vs Flagella | 15 Prominent Differences

Cilia and Flagella are the cell organelles meant for the movement of the cells or substances.

Cilia are short, slender, hair-like structures present on the cell surface of protozoan and mammalian cells.

Flagella are long, thread-like structures protruding out of the cell wall from the cytoplasm.

Cilia are also found in unicellular organisms like bacteria and protozoa.

In higher animals, they are found in the respiratory system, digestive system, reproductive system, and urinary system.

cilia vs flagella
Cilia on the surface of the epithelium
cilia vs flagella

Cilia and Flagella are cell organelles that look similar, but they have a wide range of differences

Sl. NoCharacteristicsCiliaFlagella
1AppearanceThey are short, slender, and hair-like structures.They are long, filamentous, and thread-like structures.
2OccurrencePresent all over the cell surfaceSeen at one or two ends and rarely all over the cell.
3DimensionsRanges from 1-10µm in length and less than
1µm in width
Between 5-20 µm in length and 10-30nm in width.
4DensityNumerousVery few or sometimes only one is present.
5Found inOnly in Eukaryotes and are absent in bacteria.Seen in both Eukaryotes and
6DistributionPresent in protozoa.

Larvae of Annelids, Molluscs, Echinodermates, and Platyhelminthes.

And also in the epithelium of mammals.
Present in choanocyte
of sponges, Algae,

Spermatozoa and gamete cells.
7FunctionLocomotion, circulation, aeration, signal
transformation, excretion.
Locomotion and also for adhesion in the host.
8Types1. Primary, non-
motile cilia (seen in
almost all the cells).

2. Motile cilia are seen in paramecium, Respiratory passages, the middle ear, etc.
1. Bacterial flagella.
2. Archaeal flagella
3. Eukaryotic flagella.
9Types of motion 1. Fast-moving, rotational,
show back and forth

2. Show rhythmic,
coordinated movement.

3. Ciliary movement
sweeps materials
across tissues.
1. Slow-moving,
propeller-like motion, undulating, sinusoidal movement.

2. Show independent

3. Flagellar movement propels cells forward
10Energy sourceUses ‘kinesin’, which has
ATPase activity
Obtain energy from the Proton motive force of the plasma
11Presence of NexinNexin protein is absentNexin protein is present
between the tubules to hold
them together.
12ExamplesCilia is present in paramecium.Flagells is present in euglena.
In bacteria like Escherichia coli, Pseudomonas aeruginosa

Ciliary functions vary in different organisms.

  • Besides locomotion, they are used for the movement of substances like expelling particulate matter in the respiratory tract and propulsion of food in the gut.
  • Further, they are involved in signal transformation in sensory cells like in the tongue.

Variations in the internal structure of Cilia and flagella.

The design of cilia is different in Motile and not motile cilia.

Motile cilia contain an outer membrane that encloses cilia and
fuses with the cell wall at the base.

The inner space contains a fluid matrix and has microtubules. There are 9 fused microtubule doublets that surround 2 single central microtubules (9+2).

This arrangement is collectively known as an axoneme.

Microtubule doublet contains ‘A’ tubule and ‘B’ tubule. ‘A’ tubule is a complete tubule with 13 protofilaments. The ‘B’ tubule is complete with 10 protofilaments.

However, primary or non-motile cilia have a matrix that contains 9 fused microtubules only (9+0). There is no central tubule.

On the other hand, the eukaryotic flagella show similar internal morphology to the motile cilia of eukaryotes.

It contains an ‘axoneme,’ which has a 9+2 microtubule arrangement.

Whereas the prokaryotic flagella do not have a 9+2 arrangement of microtubules.

Prokaryotic flagella are made of a protein called Flagellin and are thinner compared to eukaryotic flagella.


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