The word female comes from the Latin femella, the diminutive form of femina, meaning "woman". It is not etymologically related to the word male, but in the late 14th century the English spelling was altered to parallel that of male.[7][8]Female is also used as a noun meaning "a female organism", though describing women as females is often considered disparaging, as it makes no distinction between other animals and humans.[9][10]
Biological sex is
conceptually distinct from gender,[11][12] although they are often used interchangeably.[13][14] The adjective female can describe a person's sex or gender identity.[6]
The word can also refer to the shape of connectors and fasteners, such as screws, electrical pins, and technical equipment. Under this convention, sockets and receptacles are called female, and the corresponding plugs male.[15][16]
Defining characteristics
Females produce
spermatozoa, are produced by males.[3][17] Generally, a female cannot reproduce sexually without access to the gametes of a male, and vice versa, but in some species females can reproduce by themselves asexually, for example via parthenogenesis.[18]
Patterns of sexual reproduction include:
Isogamous species with two or more mating types with gametes of identical form and behavior (but different at the molecular level),
move. Oogamy is a form of anisogamy.[19] There is an argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for sexual reproduction.[20]
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
humans, because the female human body stores large amounts of fatty tissue near the nipples, resulting in prominent breasts. Mammary glands are present in all mammals, although they are normally redundant in males of the species.[26]
Most mammalian females have two copies of the
heterozygous and carries a Z and a W chromosome while the male carries two Z chromosomes. In mammals, females can have XXX or X.[29][30]
Mammalian females bear live young, with the exception of monotreme females, which lay eggs.[31] Some non-mammalian species, such as guppies, have analogous reproductive structures; and some other non-mammals, such as some sharks, also bear live young.[32]
In sex determination for mammals, female is the default sex, while in the poplar genus Populus the default is male.[33]
The sex of a particular organism may be determined by genetic or environmental factors, or may naturally change during the course of an organism's life.[23]
Genetic determination
The sex of most mammals, including humans, is genetically determined by the
karyotypes. During reproduction, the male contributes either an X sperm or a Y sperm, while the female always contributes an X egg. A Y sperm and an X egg produce a male, while an X sperm and an X egg produce a female. The ZW sex-determination system, where females have ZW (as opposed to ZZ in males) sex chromosomes, is found in birds, reptiles and some insects and other organisms.[23]
Environmental determination
The young of some species develop into one sex or the other depending on local environmental conditions, e.g. the sex of crocodilians is influenced by the temperature of their eggs. Other species (such as the goby) can transform, as adults, from one sex to the other in response to local reproductive conditions (such as a brief shortage of males).[34]
Evolution
See also:
binary fission, wherein a cell splits itself in half. From a strict numbers perspective, a species that is half males/half females can produce half the offspring an asexual population can, because only the females are having offspring. Being male can also carry significant costs, such as in flashy sexual displays in animals (such as big antlers or colorful feathers), or needing to produce an outsized amount of pollen as a plant in order to get a chance to fertilize a female. Yet despites the costs of being male, there must be some advantage to the process.[35]
The advantages are explained by the
Volvocales (a type of green algae) evolved from the plus mating type.[37]: 222 Although sexual evolution emerged at least 1.2 billion years ago, the lack of anisogamous fossil records make it hard to pinpoint when females evolved.[39]
Female sex organs (genitalia, in animals) have an extreme range of variation among species and even within species. The evolution of female genitalia remains poorly understood compared to male genitalia, reflecting a now-outdated belief that female genitalia are less varied than male genitalia, and thus less useful to study. The difficulty of reaching female genitalia has also complicated their study. New 3D technology has made female genital study simpler. Genitalia evolve very quickly. There are three main hypotheses as to what impacts female genital evolution: lock-and-key (genitals must fit together), cryptic female choice (females affect whether males can fertilize them), and sexual conflict (a sort of sexual arms race). There is also a hypothesis that female genital evolution is the result of pleiotropy, i.e. unrelated genes that are affected by environmental conditions like low food also affect genitals. This hypothesis is unlikely to apply to a significant number of species, but natural selection in general has some role in female genital evolution.[40]
Symbol
Main articles:
Venus symbol
The symbol ♀ (
Venus, goddess of beauty, because it resembles a bronze mirror with a handle,[41] but modern scholars consider that fanciful, and the most established view is that the female and male symbols derive from contractions in Greek script of the Greek names of the planets Thouros (Mars) and Phosphoros (Venus).[42][43]
See also
Look up female in Wiktionary, the free dictionary.
. During sexual reproduction, each parent animal must form specialized cells known as gametes...In virtually all animals that reproduce sexually, the gametes occur in two morphologically distinct forms corresponding to male and female. These distinctions in form and structure are related to the specific functions of each gamete. The differences become apparent during the latter stages of spermatogenesis (for male gametes) and oogenesis (for female gametes)....After oogenetic meiosis, the morphological transformation of the female gamete generally includes development of a large oocyte that does not move around....The ambiguous term "egg" is often applied to oocytes and other fertilizable stages of female gametes....Spermatogenesis and oogenesis most often occur in different individual animals known as males and females respectively.
. Female 1. Denoting the gamete (sex cell) that, during sexual reproduction, fuses with a male gamete in the process of fertilization. Female gametes are generally larger than the male gametes and are usually immotile (see Oosphere; Ovum). 2. (Denoting) an individual organism whose reproductive organs produce only female gametes.
^J. Richard Johnson, How to Build Electronic Equipment (1962), p. 167: "To minimize confusion, the connector portions with projecting prongs are referred to as the 'male' portion, and the sockets as the 'female' portion."
^Richard Ferncase, Film and Video Lighting Terms and Concepts (2013), p. 96: "female[:] Refers to a socket type connector, which must receive a male connector"
^David E. Sadava, H. Craig Heller, William K. Purves, Life: The Science of Biology (2008), p. 899
^Franz Engelmann, G. A. Kerkut, The Physiology of Insect Reproduction (2015), p. 29
. The origin of these symbols has long been of interest to scholars. Probably none now accepts the interpretation of Scaliger that ♂ represents the shield and spear of Mars and ♀ Venus's looking glass.