Keywords. origin of replication: particular sequence of a genome at which replication is initiated. leading strand: the template strand of the DNA double helix that is oriented so that the replication fork moves along it in the direction ' ′ lagging strand: the strand of the template DNA. double helix oriented so that the replication fork, semi-conservative replication means that when the double stranded DNA helix was replicated, each of the two double stranded DNA helices consisted of one strand from the original helix and a newly synthesized strand. It has been called the greatest experiment in biology. 2. 2. 12: At the origin of replication, topoisomerase II relaxes the supercoiled chromosome. Two replication forks are formed by the opening of the double-stranded DNA at the origin, and the helicase separates the DNA strands, which are coated with single-stranded binding proteins to keep the strands separated. Katherine Harris. Hartnell College. 1. Description of DNA replication. The human body produces billions of new cells every day. But before undergoing cell division, a cell must first copy the genetic information contained in the cell nucleus – its DNA. In - a cell is capable of copying its entire genome.