News tagged with sperm
Sea lions fuel ocean life
Like whales, sea lions are contributing to marine ecosystems in the most fundamental way possible, research by a Flinders graduate has found.
May 15, 2012 |
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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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From embryonic stem cells, a sperm replacement and easier path to genetic modification
Researchers reporting in the April 27 issue of the journal Cell have devised a new and improved method for producing genetically modified animals for use in scientific research. The method relies on haploi ...
Apr 26, 2012 |
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How sperm and eggs develop precisely 23 chromosomes each
Researchers at the University of California, Davis have discovered a key tool that helps sperm and eggs develop exactly 23 chromosomes each. The work, which could lead to insights into fertility, spontaneous ...
Apr 12, 2012 |
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Changing climate can affect fish fertility
(Phys.org) -- Warmer water temperatures can greatly increase the reproductive capacity of the widely distributed pest fish species gambusia, or mosquito fish, a new study has found.
Apr 10, 2012 |
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Whales' signals reveal retreat from ill-fated oil rig
A technique that monitors whales through the sounds they emit has answered a key issue raised by the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico two years ago this month.
Apr 06, 2012 |
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How to make high-end perfumes without whale barf
University of British Columbia researchers have identified a gene in balsam fir trees that could facilitate cheaper and more sustainable production of plant-based fixatives and scents used in the fragrance industry and reduce ...
Apr 05, 2012 |
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Ovastacin cuts off sperm binding
A study in The Journal of Cell Biology describes how a secreted enzyme helps egg cells avoid being fertilized by more than one sperm.
Apr 02, 2012 |
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Basketball-sized eyes help squids play defense
Giant and colossal squids have eyes as big as basketballs, and a Duke scientist thinks he knows why.
Mar 15, 2012 |
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Sperm can count
The speed at which the calcium concentration in the cell changes controls the swimming behavior of sperm. They can calculate the calcium dynamics and react accordingly.
Mar 07, 2012 |
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Secret of sperm quality control revealed
Yale researchers have discovered how the "guardian of the genome'' oversees quality control in the production of sperm — and perhaps in many other cells as well.
Feb 16, 2012 |
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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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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.
