Final answer:
The Dissociator (Ds) element is responsible for chromosome breakage in maize, and it can be activated by the activator element (Ac).
Step-by-step explanation:
In maize, the element responsible for chromosome breakage is known as the Dissociator (Ds) element. It can change position within the chromosome and cause random and unstable mutations.
The Ds element's ability to break chromosomes can be activated by an activator element (Ac), which acts as a transposase enzyme.