Final answer:
The term that describes dramatic, planned activities uniting aspects of an organization's culture in a single event is 'rituals'. 'Rites' is a similar term used specifically in the context of religious settings or ceremonies that have a particular analogy to religious rituals.
Step-by-step explanation:
The term used to describe dramatic, planned sets of activities that bring together aspects of an organization's culture into a single event is rituals. These events are highly structured and often serve to reinforce social bonds, cultural values, and the collective identity of an organization or community. They can be both religious and secular, and include rites of passage, rites of intensification, and other types that incorporate symbols, practices, and worldviews. Rites is the answer if the context specifically refers to religious settings or particular ceremonies within a secular context that are analogous to religious rituals.