Final answer:
The Ac (Activator) element encodes a transposase enzyme that allows it to mobilize itself and the Ds (Dissociation) element, which lacks the gene for this enzyme. Both elements are related, indicated by their sequence similarities and structural features, and the movement of Ds within the genome relies on the Ac-provided transposase.
Step-by-step explanation:
How Ac Elements Influence Ds Elements
The interaction between Ac (Activator) and Ds (Dissociation) elements is a classic example of transposable elements in genetics, particularly as it pertains to maize. Ac provides the transposase enzyme that enables both Ac and Ds to move within the genome. The Ds element lacks the gene for this enzyme, and therefore, depends on Ac for transposition. A key insight by Barbara McClintock, who won the Nobel Prize for her discovery of transposable elements, involved the observation that Ds elements can disrupt the maize Bz gene, affecting kernel coloration, only in the presence of an activated Ac element.
Ds elements are derived from Ac elements, and they share sequence similarities. Both have eleven base pair (bp) inverted repeats at their ends and cause an eight bp direct repeat upon insertion into the genome. The ability of Ds to cause 'breakage' or gene disruption is thus contingent on the presence of a functional Ac element that provides the necessary transposase.