1. Four steps of DNA replication are summarized below. Number the steps in the correct order. Each half of the DNA molecule serves as a template or pattern for the formation of a new half.

Bases in free nucleotides join with the correct bases on the two exposed chains. Cytosine always
bonds to guanine and adenine always bonds to thymine.

The two new molecules of DNA become twisted again, taking on the form of a double helix.
Bonds form between the sugars and phosphates of the newly paired nucleotides on the DNA
chains. Two identical copies of the original molecule are formed.

The double helix untwists and the bonds between the bases of the DNA molecule are broken.

The two chains of nucleotides separate from one end down, like a zipper being opened.