Final answer:
The acrosome is an important structure between the sperm head and its tail. It contains enzymes that help the sperm penetrate the egg. The flagellum, or tail, helps the sperm swim to reach the egg.
Step-by-step explanation:
The important thing between the sperm head and its tail is the acrosome. The acrosome contains enzymes that help the sperm penetrate an egg (if it reaches one). The tail of the sperm, also known as the flagellum, is responsible for propelling the sperm through the female reproductive tract to reach an egg if one is present.