Though they appear feminine to many species, asari are a mono-gendered species. During reproduction, they provide two sets of genes to their daughters in a form of parthenogenesis, with the second set modified by contact with a partner. During asari melding, an asari attunes her nervous system to her partner, giving and receiving electrical impulses through the skin until the two briefly become one unified nervous system.
This fine control over their nervous systems contributes to the asari talent for biotics. Few species can train the level of control that most asari have by nature.
Since joining the Citadel, asari prefer to mate outside their own species, claiming that this fosters development and understanding. It also reduces incidences of Ardat-Yakshi, "pure-blooded" asari who suffer a dangerous genetic disorder. If asari are compatible with life in Andromeda, that will prove several theories about the fundamental building blocks of life.