There are six major groups of enzymes. The categories are based on the types of reactions that they catalyze. What type of enzyme can join together two molecules to make a larger molecule such as a long strand of DNA

DNA ligase.

Explanation:

DNA ligase is a type of enzyme that is responsible for join together of two molecules to make a larger molecule such as a long strand of DNA. This enzyme joins the end of two DNA molecules making it a long strand of DNA. In DNA cloning process, restriction enzymes and DNA ligase enzymes are used to incorporate genes and other pieces of DNA into plasmids so we can say that DNA ligase is responsible for long strand of DNA.