AY Honors/Porifera and Cnidaria/Answer Key
From Pathfinder Wiki
< AY Honors | Porifera and CnidariaAY Honors/Porifera and Cnidaria/Answer Key /
1. Why are sponges considered animals?
The Porifera, or sponges, are multicellular filter-feeders, drawing particles out of the water column and ingesting these for nutrients. The general action of sponges, then, helps categorize them as animals, rather than as plants. However, some scientists argue that Sponges may belong in their own kingdom, due to some unique characteristics. These include the ability of many sponges to group from single cells, forming back into the full set of differentiated cells of a sponge, and the fact that isolated sponge cells cannot live alone for long (unlike colonial animals, like bryozoans, which are cooperative cells, but not necessary to one an other).