Practice question

A biocenosis, or biotic community, is the assemblage of interacting living organisms occupying a biotope. It can be partitioned by organismal group into phytocenosis for plants, zoocenosis for animals, and mycocenosis for fungi; microbiocenosis is another common subdivision. “Hydrocenosis” instead denotes a community associated with an aquatic habitat, so it is a habitat-based community rather than a taxonomic component parallel to plants, animals, and fungi. Under that intended classification, it is the item that does not belong in the list of component groups. The wording remains nonstandard and potentially confusing: aquatic communities are themselves biocenoses, and some sources may use hydrobiocenosis or hydrocenosis descriptively. Thus, it would be inaccurate to claim that living communities in water are excluded from biocenosis. The keyed content applies only when “include” means the conventional organism-based subdivisions. The underlying distinction is between classifying a community by which organisms it contains and naming it by the physical habitat in which those organisms interact.