Floating body transistor constructions, semiconductor constructions, and methods of forming semiconductor constructions

A semiconductor construction comprising:

• an electrically conductive plate;
• an expanse of semiconductor material adjacent the plate, and spaced from the plate by one or more dielectric materials;
• the expanse having a pair of prongs extending from a base portion;
• the prongs comprising conductively-doped regions;
• an insulative material between the prongs;
• a floating body transistor comprising at least a portion of the semiconductor material and at least a portion of the plate, the conductively-doped regions of the prongs being source/drain regions of the transistor, the plate comprising a gate of the transistor, and the base portion of the expanse comprising the floating body of the transistor;
• and
• pair of trenches filled with an electrically insulative material on opposing sides of prongs, the trenches extending below the base portion of the transistor and into insulative material of a semiconductor-on-insulator construction.