News tagged with sperm
Study of diving beetles suggest sperm evolution may be driven by changes in female reproductive organs
Studying female reproductive tracts and sperm in diving beetles (Dytiscidae), researchers from the University of Arizona and Syracuse University have obtained a glimpse into a bizarre and amazing world of spe ...
Feb 06, 2012 |
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Bright bills in mallards helps duck semen fight bacteria
(PhysOrg.com) -- The male Mallard duck (Anas platyrhynchos) is known for its colorful neck and a bill that ranges in color from dull green to bright yellow, depending on the amount of carotenoid pigment it con ...
Apr 15, 2011 |
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Japanese sperm cell breakthrough offers hope to infertile men
(PhysOrg.com) -- In what can only be described as cosmic forces at work, Japanese scientists working at Yokohama University, just south of Tokyo, have in the midst of a national crises, announced a major breakthrough in fertility ...
Mar 24, 2011 |
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Preliminary study suggests frequent cycling could affect male fertility
(PhysOrg.com) -- A study of men attending fertility clinics has found bicycling for five or more hours a week was associated with low sperm count and poor sperm motility.
Dec 13, 2010 |
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Which species has the largest testicles? Big secret revealed by researchers
(PhysOrg.com) -- Researchers at the University of Derby and colleagues at the University of Cambridge believe they have found which species has the largest testicles in relation to body weight on the planet ...
Nov 10, 2010 |
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Scientists discover human sperm gene is 600 million years old
Just as styles in sexy clothes or fashion change from year to year and culture to culture, "sexy" genes, or genes specific to sex, also change rapidly. But there is one sex-specific gene so vital, its function has remained ...
Jul 15, 2010 |
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Male Mexican mollies grow mustaches to attract mates
(PhysOrg.com) -- Some male Mexican molly fish sport a structure like a mustache on their top lips, which scientists have now discovered are attractive to female mollies and may represent a sexually selected ...
Jun 29, 2010 |
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Cola and unhealthy lifestyle lower sperm count
(PhysOrg.com) -- A Danish study suggests drinking a lot of cola regularly could men’s lower sperm count by almost 30 percent. The culprit does not appear to be caffeine, since coffee did not have the same ...
Mar 31, 2010 |
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Does promiscuity prevent extinction?
Promiscuous females may be the key to a species' survival, according to new research by the Universities of Exeter and Liverpool. Published today (25 February) in Current Biology, the study could solve the my ...
Feb 25, 2010 |
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Chimp and human Y chromosomes evolving faster than expected
(PhysOrg.com) -- Contrary to a widely held scientific theory that the mammalian Y chromosome is slowly decaying or stagnating, new evidence suggests that in fact the Y is actually evolving quite rapidly through continuous, ...
Jan 13, 2010 |
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Molecular Decay of Enamel-Specific Gene in Toothless Mammals Supports Theory of Evolution
(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, ...
Sep 04, 2009 |
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Unlocking the key to human fertility
Scientists at Leeds and Bradford have discovered a unique 'DNA signature' in human sperm, which may act as a key that unlocks an egg's fertility and triggers new life.
Aug 03, 2009 |
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Human sperm created from embryonic stem cells (Update)
(PhysOrg.com) -- Human sperm have been created using embryonic stem cells for the first time in a scientific development which will lead researchers to a better understanding of the causes of infertility.
Jul 08, 2009 |
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Analysis knocks down theory on origin of cell structure
(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 ...
Apr 22, 2009 |
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Insect glands may illuminate human fertilization process
Insect glands are responsible for producing a host of secretions that allow bees to sting and ants to lay down trails to and from their nests. New research from Carnegie scientists focuses on secretions from glands in the ...
May 03, 2012 |
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Sperm
The 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
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
