What is the term for a chain grouping of three or more bacterial cells?

The term that describes a chain grouping of three or more bacterial cells is "strepto." This prefix originates from the Greek word "streptos," meaning twisted or bent, which is reflective of the arrangement of the bacteria. In microbiology, "strepto" is commonly used to denote bacteria that grow in long chains, such as Streptococcus, which can appear as long formations when viewed under a microscope.

In contrast, other terms refer to different arrangements. For instance, "staphylo" refers to a cluster or grape-like arrangement of bacterial cells, typically associated with Staphylococcus species. "Diplo" describes a pairing of two bacterial cells, as seen in Diplococcus, where two cells remain attached. "Mono" refers to a single bacterial cell, highlighting individual organisms rather than groupings. Therefore, the correct term for a chain of three or more cells is indeed "strepto."