News tagged with females

Related topics: offspring , women , proceedings of the royal society b , sperm , eggs

Outcomes vary with transcatheter valve surgery

(HealthDay)—Of more than 12,000 patients who underwent transcatheter aortic valve replacement, nearly one-quarter died within a year, while roughly 4 percent had a stroke, new research reveals. However, ...

Mar 11, 2015
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ACL injuries in female athletes traced to genes

Female athletes endure two to eight times more anterior cruciate ligament (ACL) injuries than male athletes. Now it appears that genes are a major factor, according to Dr. William Landis, G. Stafford Whitby ...

Mar 10, 2015
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Diet key to lifespan and fertility

It may be possible to live longer and increase fertility by manipulating diet, according to world-first research in mice from the University of Sydney's Charles Perkins Centre.

Mar 03, 2015
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Female

Female (♀) is the sex of an organism, or a part of an organism, which produces mobile ova (egg cells). The ova are defined as the larger gametes in a heterogamous reproduction system, while the smaller, usually motile gamete, the spermatozoon, is produced by the male. A female individual cannot reproduce sexually without access to the gametes of a male (an exception is parthenogenesis). Some organisms can reproduce both sexually and asexually.

There is no single genetic mechanism behind sex differences in different species and the existence of two sexes seems to have evolved multiple times independently in different evolutionary lineages. Other than the defining difference in the type of gamete produced, differences between males and females in one lineage cannot always be predicted by differences in another. The concept is not limited to animals; egg cells are produced by chytrids, diatoms, water moulds and land plants, among others. In land plants, female and male designate not only the egg- and sperm-producing organisms and structures, but also the structures of the sporophytes that give rise to male and female plants.

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