Why are enzymes needed during DNA replication?

An enzyme is a molecule that speeds up a reaction. In the case of DNA reproduction, enzymes not only speed up the reaction, they are necessary for DNA reproduction.

Explanation:

An enzyme is a molecule that speeds up a reaction. In the case of DNA reproduction, enzymes not only speed up the reaction, they are necessary for DNA reproduction.

Recall that DNA is a long strand with a many repeating base pairs. In order for DNA to reproduce, the base pairs must be split apart. One half of the strand is then used as a template to build a new strand of DNA.

The enzyme helicase is responsible for splitting DNA along the base pairs. Helicase moves along the DNA strand unzipping the strand just as a zipper.

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.