NCBI Bookshelf. Molecular Biology of the Cell. New York: Garland Science; In most species, there are just two types of gamete , and they are radically different. The egg is among the largest cells in an organism, while the sperm spermatozoon , plural spermatozoa is often the smallest. The egg and the sperm are optimized in opposite ways for the propagation of the genes they carry.
The penis grows enlarged and firm, the skin of the scrotum is pulled tighter, and the testes are pulled up against the body. As sexual arousal and stimulation continues, the glans of the erect penis will swell wider. As the testes continue to rise, a feeling of warmth may develop around them and the perineum. With further sexual stimulation, the heart rate increases, blood pressure rises, and breathing becomes more rapid.
Sperm cells are gametes sex cells that are produced in the testicular organ gonad of male human beings and animals. Like the female gamete Oocyte , sperm cells carry a total of 23 chromosomes that are a result of a process known as meiosis. In both animals and human beings, among many other organisms, these cells are involved in the sexual mode of reproduction which involves the interaction of male and female gametes.
Sperm is the male reproductive cell. In the types of sexual reproduction known as anisogamy and its subtype oogamy , there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoon , whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells cannot divide and have a limited life span, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote.