News tagged with sperm
Giant kraken lair discovered
Long before whales, the oceans of Earth were roamed by a very different kind of air-breathing leviathan. Snaggle-toothed ichthyosaurs larger than school buses swam at the top of the Triassic Period ocean food ...
Space & Earth / Earth Sciences
Oct 10, 2011 |
4.6 / 5 (40) |
66
|
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 |
4.7 / 5 (20) |
11
|
Scientists warn of unseen deepwater oil disaster
(AP) -- Independent scientists and government officials say there's a disaster we can't see in the Gulf of Mexico's mysterious depths, the ruin of a world inhabited by enormous sperm whales and tiny, invisible ...
May 31, 2010 |
4.9 / 5 (17) |
19
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 |
4.6 / 5 (17) |
42
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 |
4.3 / 5 (15) |
6
|
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 |
4.8 / 5 (12) |
3
|
Giant predatory whale named for 'Moby Dick' author
(AP) -- Scientists have discovered an ancient whale whose bite ripped huge chunks of flesh out of other whales about 12 million years ago - and they've named it after the author of "Moby Dick."
Other Sciences / Archaeology & Fossils
Jun 30, 2010 |
4.9 / 5 (11) |
2
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 |
4.8 / 5 (11) |
9
|
The epigenetic influence of the father
(PhysOrg.com) -- Scientists from the Friedrich Miescher Institute for Biomedical Research (FMI) shed light on the highly debated question whether fathers transmit epigenetic information to their offspring. ...
Medicine & Health / Medical research
May 28, 2010 |
4.3 / 5 (12) |
1
|
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 |
4.6 / 5 (11) |
8
|
Faecal attraction: Whale poop fights climate change
Southern Ocean sperm whales are an unexpected ally in the fight against global warming, removing the equivalent carbon emissions from 40,000 cars each year thanks to their faeces, a study found on Wednesday.
Jun 15, 2010 |
4 / 5 (12) |
5
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 |
5 / 5 (9) |
0
|
Sea lampreys jettison one-fifth of their genome
(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 ...
Jul 20, 2009 |
4.9 / 5 (9) |
0
Experts fear long oil effect on marine life, food chain
Scientists studying the massive BP oil spill fear a decades-long, "cascading" effect on marine life that could lead to a shift in the overall biological network in the Gulf of Mexico.
Jul 18, 2010 |
4.1 / 5 (10) |
32
Size did matter -- evidence of giant sperm found in microfossils
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 ...
Jun 18, 2009 |
4.9 / 5 (8) |
1
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.
