How would DNA replicate if it were single stranded?

Suppose that DNA did not have a double helix structure, and instead DNA was single-stranded. Imagine that a cell with this single stranded DNA was ready to begin cell division. How could a cell replicate single stranded DNA so the daughter cells could receive an exact copy of the genes present in the original cell? Use your answer to explain why it is an advantage for DNA to have a double helix structure with paired nucleotides.