Which structure is commonly known as the sperm tail?

The structure commonly known as the sperm tail is the flagellum. Flagella are long, whip-like appendages that enable cells to move. In sperm cells, the flagellum plays a crucial role in propelling the sperm through the female reproductive tract to reach and fertilize the egg. The motion of the flagellum is coordinated and propels the sperm forward in a swimming motion, making it essential for reproduction.

Each of the other options refers to different cellular structures with distinct functions. Cilia are similar to flagella but are typically shorter and occur in greater numbers on the surface of cells, often aiding in movement of substances across the cell surface rather than in cellular locomotion. Centrioles are involved in cell division and the organization of the spindle fibers that separate chromosomes, while lysosomes are cellular organelles containing enzymes for digesting waste materials and cellular debris. Understanding these differences highlights the specific role of flagella in cellular mobility, particularly in the context of sperm function.