News tagged with sperm
Whale dies on Belgian beach
A 13-metre (42-foot) sperm whale died Wednesday after washing up on a Belgian beach, the country's Royal Institute of Natural Science said.
Feb 08, 2012 |
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Without second wave of brown fat, young mice can't live without mama
For all those who have wondered where they'd be without their mothers, a study reported in the February Cell Metabolism puts a whole new spin on the question. Mice whose mothers pass along a mutant copy of a single imprin ...
Feb 07, 2012 |
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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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Male spiders of one species lose their genitals after sex to increase sperm count in females
(PhysOrg.com) -- Researchers have known for some time that the male sex organ, called a palp, in orb-web spiders is often broken off during copulation with females; what hasn’t been so clear is why. ...
Feb 02, 2012 |
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Sexual healing? Not likely
(PhysOrg.com) -- A new study shows the production of sperm is more biologically taxing than previously thought, and expending energy on it has significant health implications.
Jan 30, 2012 |
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Ultrasound male contraceptive, overlooked for decades, confirmed to work
Imagine a contraceptive that could, with one or two painless 15-minute non-surgical treatments, provide months of protection from pregnancy. And imagine that the equipment needed were already in physical therapists' ...
Jan 30, 2012 |
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Renegade sperm donor triggers US probe
A California man who donates his sperm for free to couples who want to have a baby is being investigated by US regulators but insists he will continue his efforts as a matter of goodwill.
Jan 28, 2012 |
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Scientists reveal how females store sperm for decades
(PhysOrg.com) -- Scientists have discovered that all sorts of females – from birds to reptiles to insects – have a nifty trick to prolong the lifespan of sperm, letting them store it for weeks, months ...
Jan 26, 2012 |
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Cruise ship threatens marine paradise
(AP) -- Stone fortresses and watchtowers which centuries ago stood guard against against marauding pirates loom above pristine waters threatened by a new and modern peril: fuel trapped within the capsized ...
Jan 20, 2012 |
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Scientists link dietary DHA to male fertility
Who knew that male fertility depends on sperm-cell architecture? A University of Illinois study reports that a certain omega-3 fatty acid is necessary to construct the arch that turns a round, immature sperm cell into a pointy-headed ...
Jan 09, 2012 |
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Men with deep voice may be lacking in sperm: study
(Medical Xpress) -- Women look for tall, dark and handsome. Those chiseled features and that deep sexy voice have gained the attention of women for generations. However, a new study published in PLoS ONE shows ...
Jan 09, 2012 |
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Researchers identify environmental exposure to organochlorines may impact male reproduction
Melissa Perry, Sc.D., M.H.S., professor and chair of the Department of Environmental and Occupational Health at the GW School of Public Health and Health Services and adjunct associate professor at the Harvard School of Public ...
Jan 09, 2012 |
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Scientists record electrical currents that control male fertility
Performance anxiety? Not for this human sperm.
Dec 29, 2011 |
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Fertile sperm donor draws criticism from FDA, docs
(AP) -- Physicians and the federal government cited the case of a San Francisco Bay area man who has fathered 14 children as an example of the risks posed by the informal market for sperm donations, which doctors consider ...
Dec 20, 2011 |
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Study finds evidence of sperm whale culture
Differences in the patterned clicks that sperm whales use to communicate with each other seem to be down to culture and not genetics, say researchers.
Dec 05, 2011 |
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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.
