The double-helix pattern of DNA results from two strands of DNA winding around each other like a twisted ladder with base-pair rungs down the center and sugar-phosphate supports along the sides .
In 2018 , scientists discovered that human DNA can and does sometimes exist in a form other than a doublehelix . The DNA form , labeled an i-motif , is thought to be unique to human cells and plays some kind of role in regulating when genes are turned on and off .