Related topics: stem cells
Sperm
hideThe term sperm is derived from the Greek word (σπέρμα) sperma (meaning "seed") and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid 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 totipotent zygote is formed with the potential to develop into a new organism.
The spermatozoa of animals are produced through spermatogenesis inside the male gonads (testicles) via meiotic division. They are carried out of the male body in a fluid known as semen. Mammalian sperm cells can live for up to 3 days inside the female reproductive system.[citation needed]
Sperm cells in algal and many plant gametophytes are produced in male gametangia (antheridia) via mitotic division. In flowering plants, sperm nuclei are produced inside pollen.
For more information about Sperm, read the full article at
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News tagged with sperm
Molecular Decay of Enamel-Specific Gene in Toothless Mammals Supports Theory of Evolution
Sep 04, 2009 |
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(PhysOrg.com) -- Biologists at the University of California, Riverside report new evidence for evolutionary change recorded in both the fossil record and the genomes (or genetic blueprints) of living organisms, ...
Sea lampreys jettison one-fifth of their genome
Jul 20, 2009 |
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(PhysOrg.com) -- Researchers have discovered that the sea lamprey, which emerged from jawless fish first appearing 500 million years ago, dramatically remodels its genome. Shortly after a fertilized lamprey ...
Soy foods are associated with lower sperm concentrations
Jul 24, 2008 |
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Men who eat an average of half a serving of soy food a day have lower concentrations of sperm than men who do not eat soy foods, according to research published online in Europe's leading reproductive medicine journal, Human Re ...
Biologists discover gene behind 'plant sex mystery'
Biology /
Oct 22, 2008 |
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An enigma – unique to flowering plants – has been solved by researchers from the University of Leicester (UK) and POSTECH, South Korea. The discovery is reported in the journal Nature on 23 October 2008. ...
Size did matter -- evidence of giant sperm found in microfossils
Jun 18, 2009 |
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The mystery of giant sperm present in some living animal groups today has now taken on a new dimension -- in one group of micro-crustaceans new evidence shows that it is a feature at least 100 million years ...
Laptops Linked to Male Infertility
Jun 12, 2009 |
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While fatherhood might be far from the minds of most young men, behavior patterns they establish early on may impact their ability to become a dad later in life. Excessive laptop use tops this list of liabilities, ...
Analysis knocks down theory on origin of cell structure
Apr 22, 2009 |
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(PhysOrg.com) -- Understanding how living cells originated and evolved into their present forms remains a fundamental research area in biology, one boosted in recent years by the introduction of new tools ...
Study Positively Identifies Giant Squid Presence in Gulf of Mexico
Sep 21, 2009 |
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(PhysOrg.com) -- During a recent research cruise, a rare giant squid was captured in the Gulf of Mexico.
Israeli sperm bank posts diminishing returns
May 11, 2009 |
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Wall Street giants are not the only banks hit by diminishing assets. New research for an Israeli sperm bank shows that depositors are 40 per cent less fertile than a decade ago, the Haaretz daily reported.
The egg makes sure that sperm don't get too old
Mar 25, 2009 |
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In contrast to women, men are fertile throughout life, but research at the Sahlgrenska Academy, University of Gothenburg, Sweden, has now shown that a fertilising sperm can get help from the egg to rejuvenate. The result ...
Thieving whale caught on video gives rare clues about hunting strategy, sound production
May 21, 2009 |
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For decades scientists have been intrigued by the variety of sounds emitted by sperm whales, partly due to a popular theory that suggests that the sounds might contain information about the animals' size. ...
Triangles Go Underwater and Supersonic
Jun 30, 2009 |
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(PhysOrg.com) -- The seemingly effortless way dolphins and porpoises slice through the water and the unique capabilities of the supersonic Concorde airplane have more in common than one might think.
Daily sex helps to reduce sperm DNA damage and improve fertility
Jun 30, 2009 |
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Daily sex (or ejaculating daily) for seven days improves men’s sperm quality by reducing the amount of DNA damage, according to an Australian study presented today (Tuesday) to the 25th annual meeting of the European Society ...
Sperm donor passed on sudden death heart defect
Oct 20, 2009 |
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(AP) -- A sperm donor passed on a potentially deadly genetic heart condition to nine of his 24 children, including one who died at age 2 from heart failure, according to a medical journal report.
Jumping genes discovery 'challenges current assumptions'
Jun 12, 2009 |
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Jumping genes do most of their jumping, not during the development of sperm and egg cells, but during the development of the embryo itself. The research, published this month in Genes and Development, "challenges standard assump ...
