Answer: Gap junctions are commonly found in Single unit smooth muscle only.
Explanation:
Gap junctions are specialized proteins channel in the cell membranes that allow ions and molecules to move through between adjacent cells. They are found in single unit smooth muscle. This type of muscles are found in the uterus, gastrointestinal tracts and bladder. They contain gap junctions to synchronise membrane depolarization and contracts so that the muscles contracts as single unit