Sperm

Sperm is the male reproductive cell, or gamete, in anisogamous species (species in which there is a significant difference in size between male and female gametes). The term is derived from the Greek word "sperma" meaning "seed". Sperm cells contribute approximately half of the genetic information to the offspring. The other half is contributed by the female gamete, the egg.

Structure and formation

Sperm cells are haploid (they have half the number of chromosomes as other body cells). They are produced by a process called spermatogenesis, which takes place in the male gonads (specifically the testes). The process involves the division of a diploid spermatogonium into two haploid spermatocytes, which further divide to produce four haploid spermatids. These spermatids mature into spermatozoa, also known as sperm cells.

Function

The primary function of sperm is to reach and fertilize the egg, thus achieving sexual reproduction. This is facilitated by the unique structure of the sperm cell, which is designed for mobility and DNA delivery. The sperm cell consists of a head, which contains the genetic material, a midpiece, which provides energy, and a tail, which propels the sperm.

Sperm and fertility

The quality and quantity of sperm are important factors in male fertility. Factors that can negatively affect sperm quality include age, disease, lifestyle factors (such as smoking and alcohol), and environmental toxins. Treatments for poor sperm quality or quantity include medication, surgery, and assisted reproductive technologies such as in vitro fertilization.

See also

• Sperm competition
• Sperm donation
• Sperm bank
• Sperm motility
• Semen quality

Sperm

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  Complete diagram of a human spermatozoa
• Human sperm under microscope
  Human sperm under microscope
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  Sperm and egg
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  Sperm head dimensions
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  Sperm stained
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  Plant sperm