What reaction involves breaking covalent sugar-phosphate linkages between nucleotides in nucleic acids?

The reaction that involves breaking covalent sugar-phosphate linkages between nucleotides in nucleic acids is best described by the term "hydrolyze." Hydrolysis refers to the chemical reaction in which a compound reacts with water to break down into its components. In the context of nucleic acids, this process involves the addition of a water molecule, which facilitates the breaking of the covalent bonds connecting the sugar and phosphate groups of adjacent nucleotides.

When these bonds are hydrolyzed, it results in the separation of individual nucleotides from the nucleic acid strand. This is a critical step in various biological processes, such as DNA replication and RNA degradation.

The other terms do not accurately describe this process. For instance, "cleave" generally refers to any form of breaking or cutting without specifying the involvement of water and may not denote the specific biochemical reaction here. "Condense" describes the formation of bonds or molecules, particularly in dehydration synthesis, rather than breaking bonds. "Polymerize" refers to the process of linking monomers to form polymers, which is the opposite of breaking them apart. Therefore, hydrolyze is the most appropriate term for the action described in the question.