Dna polymerase contains a built-in “proofreading” tool, which acts in a manner similar to a word processor spell-checker. what could happen if this tool didn’t exist?

The cell will undergo mutation.

Explanation:

DNA polymerases are the enzymes that are responsible for the DNA replication. These polymerases are also used for the proof reading ability of the enzyme.

The proofreading ability can occur in both 3' to 5' direction and 5' to 3' direction. These proofreading ability detects the mismatched base pair and removes them. The chances of mutation are decreased by the proofreading ability of enzyme. The absence of this enzymes leads to the large number of mutations and cause cell death.

as in mitosis, dna replication occurs during interphase.   in meiosis, it occurs specifically in s phase of interphase 1.