What are biological evidences?

The crime's biological traces: blood (the violence's marker — the stains, the spatter, the drops); semen (the sexual offences' core — the stains, the swabs); saliva (the bites, the cigarette ends, the stamps — the amylase's detection); urine-and-faeces (the scene's presence); vaginal-and-anal secretions (the swabs of the sexual offences); hair-with-roots (U6's trace-but-biological bridge); tissue-and-bone (the body's fragments); vomit (the poisoning's faces). The evidence's forms: the liquid, the stains, the dried, the mixed.