The main difference between cilia and flagella is that cilia are short appendages present in a cell resembling a hair while flagella are also hair-like appendages, but they are long and very complex.
Both cilia and flagella are hair-like appendages extending through the outer surface of a cell. They have many differences in their structure, number per cell, size and method of breathing. In fact, both of these structures extend from the cell membrane. Both are locomotory structures. They also help in the various functions of cell-like respiration, circulation, excretion, movement, etc. Cilia and flagella are found in eukaryotic cells. But for prokaryotic cells, only flagella are found. Both of these structures are not found in plants.
Cilia play their key role in locomotion, but they are also helpful in respiration and some other functions. Flagella play a role only in locomotion. The length of cilia is short, and they are found abundant in number, i.e., hundreds per cell. On the other hand, flagella are longer, but they are few in number. Usually, a cell contains less than 10 flagella. The beating movement of cilia occurs in coordination with each other while flagella do not perform beating movement in coordination. They do so independently.
Nexim is a specific kind of protein which is present in cilia but not found in flagella because it is not required for the functions performed by flagella. The movement of cilia is very fast, and it is of rotational type. The movement of flagella is very slow and wave like. They perform the undulating movement. Cilia are present all around the surface of the cell. While flagella are found at both ends of the cell but sometimes they are also found across all over the surface.
|Definition||They are short outgrowths from the surface of the cell resembling like hair.||They are very long outgrowths arising from the surface of a cell. They also resemble hair.|
|Type of structure||They have a simple structure||They have a very complex structure|
|Presence||They are present across all over the surface of the cell.||They may be present at one end of the cell, at both ends of the cell or across all over the cell.|
|Length||Their length is very short. (1 to 10-micron meter).||They are very long. (5 to 16-micron meter).|
|Types||Cilia are of two types, i.e., motile and nonmotile. Motile cilia are present in the respiratory tract and ear cells while nonmotile cilia are present in all the other cells. They act as an antenna and receive signals from surroundings.||Flagella are of three types, i.e., bacterial flagella, archaeal flagella, and eukaryotic flagella. Bacterial flagella are found in some bacteria. Eukaryotic flagella are present in eukaryotic cells only. Archaeal flagella are just like the bacterial type, but they do not have a central channel.|
|In which type of cell they are present||They are present only in eukaryotic cells.||They are found in both eukaryotic and prokaryotic cells.|
|Type of protein present||Nexim is a protein which is present in the cilia.||They are made up of flagellin protein.|
|Functions||Their major function is locomotion. But they also perform other functions like aeration, respiration, removal of secretions, mating in some organisms, excretion, and circulation.||They play a role in locomotion only and do not perform any other function.|
|Type of movement||Their movement is a very fast and rotational type.||Their movement is very slow and undulating. Sometimes called a wave-like movement.|
What are Cilia?
Cilia are very short hair like outgrowths from the surface of a cell. They are found in all the eukaryotic type of cells. Cilia are classified into two types, i.e., motile cilia and nonmotile cilia. Motile cilia are movable, and mainly they are found in the upper and lower respiratory tract, lungs and middle ear. They remove the secretions and keep the airway clean from mucus and dust. Thus they make the breathing process easy and prevent us from infections.
In the middle ear, their function is to remove the wax which is pushed towards the external ear canal with the movements of the jaw. Movements of sperm also take place with the help of cilia. Non-motile cilia act like an antenna. They receive signals from the surrounding cells. In the eye cells, nonmotile cilia are also present which facilitate the transportation of molecules among the photoreceptors. Cilia are very short, and usually, they are abundant in number in a cell.
What are Flagella?
Flagella are very long hair like outgrowths from the surface of a cell, and they are very complex in structure. They are made up of flagellin protein. They play a key role in the motility of the cell and present in both eukaryotic and prokaryotic cells. They perform very slow wave-like movement sometimes called an undulating movement. Flagella may be found at one end of the cell, at both ends of a cell or across all over the surface of the cell. They are found less in number. A cell has less than ten flagella. Flagella are divided into three types, i.e., bacterial flagella, archaeal flagella, and eukaryotic flagella.
Bacterial flagella are found in various bacterial species like Salmonella, Shigella, E.Coli, Vibrio, etc. They have a filament-like structure resembling a helical. Bacteria move with the help of these flagella. Archaeal flagella are just like bacterial flagella, but they do not have a central channel which is present in all bacterial flagella. Eukaryotic flagella are a very complex proteinaceous structure that performs back and forth beating movement. They are found in eukaryotic cells. In the human body, its example can be given in terms of sperm cell which moves towards the egg with the help of this flagella. Flagella have three body parts, i.e., filament, hook, and basal body.
Key Differences between Cilia and Flagella
- Cilia are very short hair like outgrowths from the surface of a cell while flagella are long hair like outgrowths.
- Cilia are found in abundant number in a cell while flagella are found less in number. (Less than 10).
- Cilia are classified into two types, i.e., motile and nonmotile while flagella are classified into three types, i.e., bacterial flagella, eukaryotic flagella, and archaeal flagella.
- Cilia perform very fast rotatory movement while flagella perform the slow undulating movement.
- Cilia are present in eukaryotic cells, but flagella are present in both eukaryotic and prokaryotic cells.
Cilia and flagella both are hair-like outgrowths from the surface of a cell. It is important for biology students to know the differences between both. In the above article we came to know the clear differences between cilia and flagella.