Difference between cilia and flagella

The main difference between cilia and flagella is that cilia are a short hair-like structure that is present in large numbers in a cell, while flagella are a long-hair-like structure that are few in a cell.

Cilia against flagella

Cilia and flagella are the organelles of the cell that are structurally similar but vary in their function and size, etc. Both are the appendages of the plasma membrane of the cell and arise from the basal body. They are locomotive in structure. Cilia also play an important role in many other processes such as excretion, ventilation, circulation, and food capture, etc. Cilia have a short structure and are present in a eukaryotic cell only while flagella have a long structure and are present in both prokaryotic and eukaryotic cells. The beat pattern is also different, the cilia beat in coordination with each other while the flagella beat independently of each other.

Comparative chart

What are cilia ?

Cilia is derived from a Latin word meaning “eyelash.” It is a short, thin, hair-like appendage that is found on the entire surface of the cell. Its width is less than 1 µm and it measures between 5 and 10 micrometers long.

• Mobile ciliates:They are mobile cilia found primarily in the lungs, middle ear, and respiratory tract. They beat rhythmically and keep the airways clear of mucus and dust to make it easier to breathe freely and without irritation. They also help in the movement of sperm. The motile cilia have a 9 + 2 arrangement of the ciliary axoneme which is the microtubular backbone of the cilia and is surrounded by the plasma membrane. There are nine pairs of fused microtubules arranged in a circle, and the two unfused microtubules are present in the center of the circle. The “dynein” arms are also attached to microtubules that act as molecular motors. Any defect in the dynein arms can cause male infertility and respiratory tract problems.
• Immobile Cilia – Also known as primary cilia. They act as antennas for the cell and perform their function of receiving signals from other cells or nearby fluids. For example, in the kidney, they send signals about the flow of urine. These cilia have a 9 + 0 microtubular arrangement.

What is Flagella ?

The word flagella is derived from the Latin word meaning “whip.” They are complex organelles in the form of eyelashes that extend through the cell surface. They are composed of flagellin protein, embedded in the cell envelope. They are also locomotive in structure. They can be approximately 150 µm in length and 12-30 nm in diameter. A cell can have a single flagellum at its pole or less than 10 per cell. Flagella also consist of a hook, filament, and basal body in the parts of the body that aid in adhesion, signal transduction, sensation, and movements, etc.

Types

• Bacterial flagella: According to the presence of flagella, the attachment pattern, and the number of flagella present, bacteria are divided into different types. Atrichous is the bacterium without flagella; Monotrichous is a single polar flagella, Lophotrichous is a tuft of flagella at only one pole, Amphitrichous is a tuft of flagella at both ends, and Peritrichous is a form in which flagella surround the entire surface. They have a filamentous helical structure that turns like screws. It is found in E. coli .
• Archaeal Flagella: It is similar to bacterial flagella but lacks a central channel.
• Eukaryotic flagella: are complex projections that move back and forth. Your example is a sperm.

1. A large number of microscopic, short and thin hair-like structures that cover the entire surface of the cell are called cilia, while the long, thread-like structure that is present on the surface of the cell is called flagella.
2. Cilia are present only in a eukaryotic cell; on the other hand, flagella are found in both prokaryotic and eukaryotic cells.
3. Cilia are short in size, less than 1 µm wide and about 5 to 10 microns long, while flagella are long about 150 µm in length and 12-30 nm in diameter.
4. Cilia are numerous per cell. In contrast, there are few flagella, that is, less than 10 per cell.
5. The cilia hit in coordination with each other on the other side; flagella beat independently of each other.
6. Nexim (a protein) is present in cilia while it is absent in flagella.
7. Cilia are present on the entire surface of the cell, while flagella are present at the poles and sometimes surround the entire surface.
8. The cilia show a rotational movement like a motor, that is, they move very fast, while the flagella show a slow, sinusoidal, wavy and wavy movement.
9. Cilia play an important role in locomotion and aeration (respiration), etc., but flagella are only useful in locomotion.
10. Cilia are present in Paramecium while flagella are present in Salmonella.

Based on the discussion above, it is concluded that cilia are a short locomotor appendage of the cell surface that also helps in aeration (respiration), etc. and there are numerous per cell, while flagella are a long locomotive structure found few per cell.