News tagged with females

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

Fructose more toxic than table sugar in mice

When University of Utah biologists fed mice sugar in doses proportional to what many people eat, the fructose-glucose mixture found in high-fructose corn syrup was more toxic than sucrose or table sugar, ...

Jan 05, 2015
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Estrogen worsens allergic reactions in mice

Estradiol, a type of estrogen, enhances the levels and activity in mice of an enzyme that drives life-threatening allergic reactions, according to researchers from the National Institute of Allergy and Infectious ...

Dec 29, 2014
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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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