A sperm cell is a male reproductive cell responsible for fertilizing an egg cell in sexual reproduction. It is typically small and has a streamlined shape, which helps it swim through the female reproductive system. Sperm cells are produced in the testes and are a crucial part of the process that leads to the formation of a new organism. Each sperm cell contains genetic material from the male parent, which is passed on to the offspring during fertilization. The head of the sperm cell contains the nucleus, which holds the DNA, while the tail, or flagellum, propels it forward. This unique structure allows sperm cells to navigate toward the egg cell for successful reproduction.