Final answer:
Dictyostelium amoeboids employ chemotactic cell migration, moving purposefully towards secreted chemical signals to aggregate and form a multicellular entity.
Step-by-step explanation:
Based on the relative quick speed of cell movement observed this week (under 3 hours), we know that Dictyostelium utilize chemotactic cell migration. Dictyostelium, a group of eukaryotic amoeboids known for their unique life cycle that involves aggregating to form a multicellular organism under certain conditions, exhibit movement behavior in response to chemical signals. During the aggregation stage, individual cells stream towards a central point in response to a secreted chemical signal, an action that is a textbook example of chemotaxis. This type of movement is directed and purposeful, as the cells move towards the increasing concentration of certain chemicals to form a 'slug', which can eventually transform into a fruiting body.