Like Y-DNA STRs, autosomal STRs are counts of repeated genetic code. As autosomal DNA recombines each generation, the number of markers shared with a specific ancestor is reduced by half each generation.
Heroin acts as a lipid soluble âprodrugâ within the brain, meaning that heroin itself is inactive but it is metabolized into an active form within the body. After crossing the blood-brain barrier, heroin is metabolized into morphine, which actively binds to opiate receptors in the brain producing the high.
1 Heroin belongs to a class of drugs known as opioids, along with opium, codeine, morphine, methadone, and oxycodone.2  Heroin can come as a white or brownish powder (sometimes grainy) or as a dark brown substance (sometimes sticky) known as tar or black tar. Heroin can come as a white or brownish powder (sometimes grainy) or as a dark brown substance (sometimes sticky) known as tar or black tar. 2  Heroin is usually cut with other substances, some of which may be even stronger than heroin. 3  Purity is always inconsistent, even within one batch.