A star cluster may contain one or more galaxies.

Question

Does a star cluster have one or more galaxies

Answer 1

I don't know the precise scientific definition of star cluster and galaxy, but I believe the former term applies to much smaller agglomerations of stars than the latter, and also galaxies tend to have a lot more "stuff" in them (e.g., nebulae and random matter, including dark matter) than star clusters. Plus, and again I'm not entirely sure about this, I understand it that star clusters form simply from the mutual gravitational attraction of their stellar members, whereas galaxies tend to coalesce around supermassive black holes. 

 

In other words, a galaxy may contain one or more star clusters, but not the other way around.