By fertilization we mean the fusion of female and male reproductive cells
The sperm is the smallest cell in the human body. They are produced and mature in the male gonads (testes, testicles) under the influence of the male sex hormone testosterone. This process is called spermatogenesis. Spermatogenesis begins during puberty and lasts throughout a man’s life. With age, of course, the intensity of sperm formation decreases, but does not stop completely if the man is healthy.
A lot of sperm are produced. Within 24 hours, a healthy sexually mature man produces about 100 million sperm. In order to fully mature and be ready for fertilization, sperm need 72-74 days. That is, every man’s body contains a huge number of sperm of varying degrees of maturity.
The most important difference between a sperm and other cells in the human body is its ability to move independently. After all, in order to accomplish fertilization, he needs to independently get from the entrance to the vagina to the farthest part of the fallopian tube, where the egg is located. This distance is about 20-25 cm.