In bisexual reproduction , the female sex is the sex that provides the female reproductive cells ( egg cells ), which are fertilized by the larger number of male reproductive cells ( sperm ) and give rise to one or more offspring ( multiples ). It is marked with the Venus symbol ♀ .
Higher animals and plants usually reproduce sexually. There are many species (or higher systematic units) with asexual reproduction , but this then came about through evolution , that is, the ancestors of these groups had sexual reproduction. In most cases, the female (feminine) and male (masculine) gender are distributed among different individuals , called females and males in animals . Even species that contain true hermaphrodites ( hermaphroditism ), species with self-fertilization and monoecious plants reproduce sexually - here the individuals are both female and male, either simultaneously (simultaneously) or one after the other (successively). Bisexuality has developed independently of one another several times in the course of evolution (see also disadvantages of sexual reproduction and gender determination ).
In humans and in some other species there are occasionally individuals who cannot be clearly assigned to one of the two sexes, often formerly called hermaphrodites. In biology this is generally referred to as gynandromorphism , in humans more as intersexuality , socially as the third gender (to women and men ). In contrast to true hermaphroditism, such individuals are only able to reproduce to a limited extent or not at all.
A feminization occurs when properties are clearly in an individual over the course of its development, which correspond to the female of his species phenotypes (the feminization of men see effemination.a , the masculinization of women or men see virilization ).
In humans , the female gender is determined by four biological indicators:
- two X chromosomes , while men only have one
- the sex hormones estrogen and progestin
- the primary genital organs uterus , ovaries and vagina
- the secondary and tertiary sexual characteristics that develop in the course of life, such as the female breast (see woman , femininity , human gender differences )
In intersex people (formerly: hermaphrodites, hermaphrodites ), the primary sexual characteristics are less pronounced and cannot be clearly assigned to the female or male gender, in some cases male sexual characteristics are also present (gynandromorphism) .
- female bees develop from fertilized eggs, the male drones from unfertilized eggs (see sex determination )
- in birds, females have dissimilar sex chromosomes, while males have two identical ones
- In some crocodiles and other reptiles , the sex is determined by the incubation temperature of the eggs
In the case of seed plants , a distinction is made according to whether an individual
- only produces seeds (female),
- only produces pollen ( male ),
- or both produced ( hermaphrodite ), like the majority of all seed plants.