What is the unique cellular structure associated with sperm that allows for motility?
Flagella and motile cilia.
Flagella and cillia are the flexible extensions of the plasma membrane of sperm cells. The cell is propelled by the beating of these extensions.
The sperm cell shown above is mammalian sperm having single flagellum.
Cells have adapted many methods to transport themselves.
In the case of a sperm cell, if you look at a magnified image, you will see an appendage that resembles a tail.
That tail is known as a flagella, and the cell that has this appendage is known as a flagellate .
The flagella allows movement by creating a a whip-like motion, propelling the cell forward.
The sperm cell uses its motile ability to swim up the female reproductive tract.
Hope this helps :)