Parazoa is a taxonomic group of animals lacking definite organs, tissues, and symmetry. The word is pronounced /pærəzoʊə/ with a stress on the second syllable. The phonetic transcription of parazoa indicates that it contains two vowels that make distinct sounds. The first vowel is pronounced like in the word "pat," while the second one sounds like "go." The consonants in this word are pronounced regularly. Spelling of parazoa is necessary for clear communication amongst taxonomists and biologists.
Parazoa refers to a primary subkingdom or group within the animal kingdom that includes a distinct set of multi-cellular organisms characterized by a lack of well-defined tissues and organs. The term "parazoa" is derived from the Greek words "para," meaning beside or alongside, and "zoa," meaning animals. Thus, parazoa can be understood as animals that occupy a more primitive or simpler state of organization compared to other animal groups.
Members of the parazoa group are typically small and exhibit a relatively simple body structure. They lack true tissues, meaning that their cells are not organized into specialized groups with specific functions, as observed in advanced animals. Instead, parazoans possess loose aggregations of cells that perform general functions collectively. This feature distinguishes them from animals in the other primary animal subkingdom, Eumetazoa, which possess well-defined tissues and organs.
Examples of parazoan organisms include sponges, which are considered the most iconic representatives of this group. Sponges are structurally characterized by a hollow body with numerous pores, through which water flows, facilitating filter-feeding. Despite their simplicity, parazoans play essential ecological roles in various ecosystems, providing habitats for other organisms and contributing to nutrient cycling.
In summary, parazoa refers to a subkingdom of animals characterized by their simplicity, with organisms lacking well-defined tissues and organs. Sponges are the most prominent examples of parazoans, and these organisms play important ecological roles in nature.
One of the three groups into which the animal kingdom is divided; it includes only one phylum, the Porifera, or sponges.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "parazoa" is derived from the Greek words "para" (meaning beside or near) and "zōon" (meaning animal). Thus, "parazoa" literally translates to "beside animals" or "near animals". This term refers to a group of multicellular organisms that are considered to be one of the two major branches of animals, alongside the Eumetazoa. Parazoa includes sponge-like organisms that lack true tissues and organs.