Investigators have released chilling new sketches of unidentified murder victims - hoping details like crooked teeth and a distinctive clog could be key to solving decades-old cold case mysteries.

DNA (deoxyribonucleic acid) is the nucleic acid polymer that forms the genetic code for a cell or virus. Most DNA molecules consist of two polymers (double-stranded) of four nucleotides that each ...

DNA replication is the biological process by which an exact copy of a deoxyribonucleic acid (DNA) molecule is created and it is the basis for biological inheritance. Each of the two strands of the ...