Mass Effect & Mass Effect 2
Asari have a robust cellular regenerative system. While they do not heal faster than other species, asari are known to reach 1000 years of age.
Although asari have one gender, they are not asexual. An asari provides two copies of her own genes to her offspring. The second set is altered in a unique process called melding.
During melding, an asari consciously attunes her nervous system to her partner's, sending and receiving electrical impulses directly through the skin. The partner can be another asari, or an alien of either gender. Effectively, the asari and her partner briefly become one unified nervous system.
This unique means of reproduction is the reason asari are talented biotics. Their evolved ability to consciously control nerve impulses is very similar to biotic training. Asari believe that their offspring acquire the best qualities of the "father" from the melded genes, but evidence is anecdotal.
Asari pass through three climacteric life stages, marked by biochemical and physiological changes. The Maiden stage begins at birth, and is marked by the drive to explore and experience. Most young asari are curious and restless.
The Matron stage of life begins around the age of 350, though it can be triggered earlier if the individual melds frequently. This period is marked by a desire to settle in one area and raise children.
The Matriarch stage begins around 700, or earlier if the individual melds rarely. Matriarchs become active in their community as sages and councilors, dispensing wisdom from centuries of experience.
While each stage of life is marked by strong biological tendencies, individuals do make unexpected life choices. For example, there are Maidens who stay close to home rather than explore, Matrons who would rather work than build a family, and Matriarchs who have no interest in community affairs.