<unk>  is the age/stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct. In humans, the process of<unk> ly maturing is termed puberty.
Most multicellular organisms are unable to<unk> ly reproduce at birth (or germination), 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<unk> ly 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<unk> .<unk>  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 sex characteristics, and often represent an increase in<unk>  dimorphism. For example, before puberty, human children have flat chests, but adult females have breasts while adult males do not.
After<unk>  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. Also, while in many organisms<unk>  is strongly linked to age, many other factors are involved, and it is possible for some to display most or all of the characteristics of the adult form without being<unk> ly mature. Conversely, it is also possible for the "immature" form to reproduce (see progenesis).
Sexual maturity
Bone age
Menstrual cycle
Menopause
Fertility
Sex and illness
Menstruation
Tanner stage