Living things have cell organelles. These organelles play a crucial role in various cellular functions. Cilia and flagella are external structures found on these cell organelles.
These external structures help to enhance locomotion in cells. Besides that, these external structures in cells play a vital role during respiration, excretion, capturing of food, and circulation.
So, what is the main difference between cilia and flagella? The former prevents accumulation of dust inside the breathing tubes while the latter help to propel sperm cell through the female reproductive system.
But many learners find it hard to differentiate these locomotory structures. This article provides a detailed explanation of the differences between cilia and flagella in tabular form.
Comparison Table (Cilia vs Flagella)
Basic Terms | Cilia | Flagella |
Description | Cilia have hair-like appendages that extend from the surface of the living cell. | Flagella have thread-like appendages on the surface of a living cell. |
Length | Short 5-10nm | Long 150nm |
Origin | Latin word eyelash | Latin word whip |
Singular form | Cilium | Flagellum |
Found in | Eukaryote cell | Both eukaryote and prokaryote cells. |
Distribution | In protozoans of class ciliate and ciliated epithelium of the metazoan.
In larva of certain Platyhelminthes, Echinodermata, mollusk and annelid. |
In certain bacteria cells.
In some protozoan’s class of Flagellata, choanocyte of the sponges, spermatozoa of the metazoan. In some plants like algae In gamete cells |
Thickness | Greater diameter of about 0.3 to 0.5 um. | The thin diameter of about 0.02 to 0.025 um. |
Number | Numerous | Less in number |
Density | Many per cell | Few per cell |
Position on cell | Occur throughout the cell surface | Occur at one end or two ends or all over the cell. |
Organization | Possess a central bundle of microtubules where nine outer doublet microtubules surround a central pair of singlet microtubules. | Prokaryotic flagella are simpler structures made up of flagellin |
Beating synchronization | Cilia beat in a coordinated rhythm either simultaneously (synchronous) or one after the other (metachronous). | They beat independently of each other. |
Motion Type | Fast rotational movement | Prokaryotes experience rotary movement. Eukaryotes experience bending movement. |
Swimming motion | Cilia move like the breast stroke | Flagella move in an oar-like style. |
Energy Production | Uses kinesin that contains ATPase activity for producing energy to enhance movement. | Powdered by the proton-motive force created by plasma membrane in prokaryotes. ATP has driven in eukaryotes. |
Types | Non-motile cilia
Motile cilia |
Bacterial
Archaeal Eukaryotic |
Purpose | Help to promote movement along the outer surface of the cell. Foster feeding circulation and aeration. |
Help in locomotion only |
Function | Cilia in the mammalian system not for locomotion. | The extent from the plasma membrane and are used to move an entire cell. |
Cross-section | Nexin arm present. | Nexin arm absent. |
Examples | Cilia present in Paramecium | Flagella present in Salmonella |
Diseases | Cognitive impairment
Retinal degeneration Hearing loss Anosmia Craniofacial abnormalities Lung and airway abnormalities Infertility Polydactyly Pancreatic cysts |
Infertility Foodborne illness |
What Are Cilia?
Cilia are short hair-like structures present in large numbers in the eukaryotic cells. Cilia are grouped into non-motile cilia and motile cilia.
Non-motile cilia occur in animal cells. They are distributed around the sensory organs like the eyes and nose. Motile cilia are found in large numbers on the surface of cells to beat coordinated waves.
Motile cilia in the trachea sweep mucus to prevent dirt from entering the lungs. Motile cilia in the fallopian tube enhance the movement of the ovum towards the uterus from the ovary.
What Are Flagella?
Flagella are long lash-like structures emerging from the surface of the cell. The structure is made up of protein flagellin. It helps in the locomotion of prokaryotic and eukaryotic cells.
Flagella are grouped into bacterial, eukaryotic, and archaeal. Bacterial and archaeal flagella are responsible for the movement of cells.
The movement of cells to different locations is important during feeding, circulation, and reproduction. Mammalian sperm uses flagella to propel them towards the ovum.
Main Differences between Cilia and Flagella
- Cilia are numerous in a single cell. Flagella are fewer in a single cell.
- Cilia are short hair-like structures. Flagella are long whip-like structures.
- Cilia are shorter than flagella.
- Cilia occur in prokaryotic cells whereas flagella occur in both prokaryotic and eukaryotic cells.
- Cilia beat in coordination while flagella beat independently.
- Cilia display sweeping movement while flagella show undulatory movement.
Similarities between Cilia and Flagella
- Both arise from the basal body.
- Both outgrow from the plasma membrane
- Both have axoneme and a central filament
- The primary function is locomotion
In Conclusion
Cilia and flagella are structurally identical cell organelles. These structures play a vital role in the locomotion of cells. The main difference between cilia and flagella is based on their function and shape.
Understanding their structural and functional differences is important. You can also use their size, number, and mode of beating to tell the differences.
More Sources and References
- https://www.ncbi.nlm.nih.gov/books/NBK21698/
- https://www.thoughtco.com/cilia-and-flagella-373359
- https://en.wikipedia.org/wiki/Cilium
- https://www.news-medical.net/life-sciences/The-Organization-and-Utility-of-Eukaryotic-Cilia-and-Flagella.aspx