Sexual maturity
Sexual maturity is the stage at which an organism can reproduce. It is sometimes considered synomous with adulthood, though the two are distinct. In humans, the process of sexually maturing is termed puberty.Most multicellular organisms are not born (or germinated) able to sexually reproduce, and depending on the species, it may be days, weeks, or years until their bodies are able to do so. Also, certain cues may cause the organism to become sexually mature. They may be external, such as drought, or internal, such as percentage of body fat (such internal cues are not to be confused with hormones which directly produce sexual maturity).
Sexual maturity is brought about by a maturing of the reproductive organs and the production of gametes. It may also be accompanied by a growth spurt or other physical changes which distinguish the immature organism from its adult form. These are termed secondary sexual characteristics, and often represent an increase in sexual dimorphism. For example, human children have flat chests, but adult females have breasts while adult males do not.
After sexual maturity is achieved, it is possible for some organisms to become infertile, or even to change their sex. Some organisms are hermaphrodites and may or may not be able to produce viable offspring (see perfect). Also, while in many organisms sexual maturity is strongly linked to age, many other factors are involved, and it possible for some to display most or all of the characteristics of the adult form without being sexually mature. Contrariwise, it is also possible for the "immature" form to reproduce (see neoteny).