Organisms of many species are specialized into male and female varieties, each known as a sex.
The gametes produced by wikepedia organism define its sex: Individual organisms which produce both male and female gametes are termed hermaphroditic. Physical differences are often associated with the different sexes ladyboycock pictures an organism; these sexual dimorphisms can reflect the different reproductive pressures the sexes experience.
Sex position - Wikipedia
For instance, mate choice and sexual selection can accelerate the evolution of physical differences between the sexes. Among humans and other mammalsmales typically carry an X and a Y chromosome XYwhereas females typically carry two X chromosomes XXwhich are a part of the XY sex-determination system.
Humans may also be intersex. Other animals have different sex-determination systemssuch as sex ZW system in birds, the X0 system in insects, and various environmental systemsfor example in crustaceans. Fungi may also have more complex allelic mating systems, with sexes not accurately described as male, female, or hermaphroditic.
One of wikepedia basic properties of life is reproduction, the capacity to generate new sex, and sex is an aspect of this process.
Life has evolved from simple stages to more complex ones, and so have the reproduction mechanisms. Initially the reproduction was a replicating process that consists in producing new individuals that contain the same genetic information as the original or parent individual.
This mode of reproduction is called asexualand it is still used by many species, particularly unicellular, but it is also very common in multicellular organisms, including many of those with sexual reproduction.