The key difference between flagella and flagellum is that flagellum is the singular form, referring to one such structure, while flagella is the plural form, referring to multiple such structures.
Understanding Flagella and Flagellum
Let's explore these terms in more detail:
Flagellum (Singular)
- A flagellum is a single, long, thin, filamentous appendage.
- It's described as being twisted spirally in an open, regular wave-form.
- According to the reference, it is about 0.02 µm thick and usually several times the length of the bacterial cell.
- The primary function of a flagellum is locomotion, enabling movement in bacteria.
Flagella (Plural)
- Flagella refers to multiple flagella on a bacterial cell.
- These appendages are collectively described as organs of locomotion.
- Bacteria can have one flagellum (monotrichous), a cluster of flagella at one end (lophotrichous), flagella at both ends (amphitrichous), or flagella all over the cell (peritrichous).
Key Differences Summarized
Here is a table summarizing the differences:
| Feature | Flagellum | Flagella |
|---|---|---|
| Number | Singular (one) | Plural (more than one) |
| Definition | A single filamentous appendage | Multiple filamentous appendages |
| Function | Individual locomotion unit | Collective locomotion units |
| Use | Used to describe a single structure on bacteria. | Used to describe multiple flagella collectively on bacteria. |
Practical Insights
- A bacterium with a single flagellum uses it to propel itself in a corkscrew-like motion.
- Multiple flagella can work together in a coordinated fashion, allowing for more versatile movement, such as tumbling and changing direction.
Therefore, when discussing the movement mechanisms of bacteria, one would refer to a flagellum when talking about one such appendage and flagella when referring to multiple such structures.
