Surgery

Physiotherapy 'postcode lottery' uncovered

The amount of physiotherapy available following hip and knee replacements comes down to a 'postcode lottery' according to new research led by the University of East Anglia in collaboration with the universities of Bristol ...

Oncology & Cancer

Breast cancer recurrence score has different implications for men

The TAILORx study published last year offered good news for women with early-stage ER-positive breast cancer who scored at intermediate risk for recurrence according to a genetic assay test. The study indicated that chemotherapy ...

Psychology & Psychiatry

Ketamine reduces drinking in male, but not female, rats

The drug ketamine decreases alcohol consumption in male, but not female, rats, according to new research published in eNeuro. The findings suggest that ketamine may be a viable treatment option for male patients with an alcohol ...

page 1 from 23

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.

This text uses material from Wikipedia, licensed under CC BY-SA