Flagella are hair-like protrusions from the cell membrane. They are larger compared to the cilia and cause cell movement through whiplash-like movement. The singular form of flagella is the flagellum. Flagella are longer than cilia, measuring about 15 µm for flagella compared to cilia which are 5 µm to 10 µm in diameter. Flagella (singular: flagellum) are long, slender appendages that stick out from certain cells , helping them move through their surroundings. Picture a bacterium twirling through water or a sperm cell racing toward an egg—these feats are powered by flagella. But movement isn’t their only trick. Across the three domains of Bacteria, Archaea, and Eukaryota, the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word flagellum means "whip" to describe its lash-like swimming motion. Flagella are fascinating microscopic, whip-like projections that play a critical role in the locomotion and sensory activities of cells. In this guide, we will delve into what is flagella, discussing its structure of flagella, flagella function, and the captivating dynamics of flagellar movement.
