The male reproductive system creates sperm that is manufactured in the seminiferous tubules within each testicle. The head of the sperm contains the DNA, which when combined with the eggs DNA, will create

Sperm are male reproductive cells that are one-half responsible for creating life. Read on to discover some facts about sperm and male fertility.

Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, which are known as spermatozoa, while some red algae and fungi produce non-motile sperm cells, known as spermatia. Flowering plants contain non-motile sperm inside pollen, while some more basal plants like ferns and some gymnosperms have motile sperm.Sperm cells form during the process known as spermatogenesis, which in amniotes (reptiles and mammals) takes place in the seminiferous tubules of the testes. This process involves the production of several successive sperm cell precursors, starting with spermatogonia, which differentiate into spermatocytes. The spermatocytes then undergo meiosis, reducing their chromosome number by half, which produces spermatids. The spermatids then mature and, in animals, construct a tail, or flagellum, which gives rise to the mature, motile sperm cell. This whole process occurs constantly and takes around 3 months from start to finish. Sperm cells cannot...

a woman of rank, station, or authority: such as; the mistress of a household; the wife or daughter of a lord… See the full definition

The Alaca Höyük bronze standards are a series of bronze objects found among the grave goods in the princely tombs of Alaca Höyük. They are generally understood as cult instruments, probably to be attached to carts. Discovery From 1935–39, the Turkish archaeologists, Hamit Zübeyir Koşay and Remzi Oğuz Arık investigated the site of Alaca Höyük, near Alaca, Çorum Province. In the process they uncovered 14 tombs of the early Bronze Age, which were named the "Princely tombs" or "Kingly tombs". Numerous grave offerings were found next to the burials - individually or in pairs - including more than twenty bronze standards. Description The archaeologist Winfried Orthmann divides the standards into two main groups, one group consists of individual animals and the other of discs or rings (with or without images of animals). He subdivides these two groups based on the shape and contents of the discs or rings, and based on the type of creatures depicted. The individual animals are all deer or bulls. The feet stand on four supports which converge at a point where it probably attached to...

The Alaca Höyük bronze standards are a series of bronze objects found among the grave goods in the princely tombs of Alaca Höyük. They are generally understood as cult instruments, probably to be attached to carts. Discovery From 1935–39, the Turkish archaeologists, Hamit Zübeyir Koşay and Remzi Oğuz Arık investigated the site of Alaca Höyük, near Alaca, Çorum Province. In the process they uncovered 14 tombs of the early Bronze Age, which were named the "Princely tombs" or "Kingly tombs". Numerous grave offerings were found next to the burials - individually or in pairs - including more than twenty bronze standards. Description The archaeologist Winfried Orthmann divides the standards into two main groups, one group consists of individual animals and the other of discs or rings (with or without images of animals). He subdivides these two groups based on the shape and contents of the discs or rings, and based on the type of creatures depicted. The individual animals are all deer or bulls. The feet stand on four supports which converge at a point where it probably attached to...

In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).The intense radiation of most observed GRBs is thought to be released during a supernova or superluminous supernova as a high-mass star implodes to form a neutron star or a black hole. A subclass of GRBs appear to originate from the merger of binary neutron stars.The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeaters, are associated with magnetars within the Milky...

In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milliseconds to several hours. After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).The intense radiation of most observed GRBs is thought to be released during a supernova or superluminous supernova as a high-mass star implodes to form a neutron star or a black hole. A subclass of GRBs appear to originate from the merger of binary neutron stars.The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeaters, are associated with magnetars within the Milky...

In geology, and paleontology, Giga-annum, abbreiviated Gya (for giga years ago) is often used as an unit of time to denote length of time before the present. Specifically, one Gya is equal to 109 years ago. A unit identical to Gya is bya (for "billion years ago"), which may be in more widespread use. However, some scientists prefer Gya because it uses the SI prefix giga- and thus avoids confusion over whether the short-scale (American) billion (109) or long-scale (former British) billion (1012)