How is Porifera classified?

Sponges lack true tissues, have no body symmetry, and are sessile; types are classified based on presence and composition of spicules.

Why Porifera phylum is kept under the separate phylum?

Based on the embryological studies, sponges are proved as animals and are classified into a separate Phylum in animals. This phylum includes about 5000 species. The poriferans have a spongy appearance and are therefore called sponges. They are attached to the substratum and do not move.

What phylum has cellular level of organization?

Phylum Porifera
Phylum Porifera which includes sponges has the basic cellular level of organization.

On what level are sponges classified by?

cellular level
Sponges are at a cellular level of organization and thus do not have organs or even well-developed tissues;……

Why are sponges distinguished from sponges with cellular bodies?

It is upon close internal examination that glass sponges can be most easily distinguished from other sponges. The skeleton of an hexactinellid is made entirely of silica. While hexactinellids possess no nerve structure, they seem to be able to send electrical signals across the body through the syncytial soft tissue.

Why is the absence of tissue level organization an appropriate description for sponge organization?

Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, but similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells.

Why are sponges classified as porifera?

The name porifera means ‘pore bearer’ in Latin (a pore is a tiny hole). A sponge’s body is covered by a skin, one cell thick. This skin has lots of small pores and a few large openings. These collar cells pump water through the entire sponge and filter out food for the sponge cells to eat.

Why sponges belong to the phylum porifera?

The organisms of this phylum have channels and pores in their body that allows water to circulate through them. Complete answer: Sponges belong to phylum Porifera. Most of the cells of sponges can move within their bodies and few can change from one type to another.

Is porifera Triploblastic or Diploblastic?

Porifera is neither triploblastic nor diploblastic since Porifera contains the cellular level of organization.

How do porifera feed?

Sponges have a unique feeding system among animals. Instead of a mouths they have tiny pores (ostia) in their outer walls through which water is drawn. Cells in the sponge walls filter food from the water as the water is pumped through the body and the osculum (“little mouth”).

Why is it that the phylum Porifera considered just above the protozoan level of organization?

Which type of cell in Porifera carry nutrients to other sponge cells and take away cellular waste?

choanocytes
are sponge cells that have irregular amoeba-like shapes. They move about the mesohyl, supplying the rest of the sponge’s cells with nutrients and carrying away their wastes. The choanocytes of sponges very closely resemble a kind of protist called a choanoflagellate, shown in Figure 3.

What are the characteristics of Porifera?

Poriferans or sponges possess small pores on their entire body and some wide openings. The members of Phylum Porifera are metazoans that show a cellular organization, i.e. lack tissues and organs. An asymmetrical body is the characteristic feature of all sponges. There are approximately 5000 species in the phylum Porifera.

How many species are in the phylum Porifera?

There are approximately 5000 species in the phylum Porifera. Poriferans are simple invertebrates (lack bony structures). The majority of them are marine. Calcarea, Hexactinellida and demospongiae are the three major classes of the phylum Porifera.

What type of cell organization do sponges have?

Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions, but similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells. This is the simplest kind of cellular organization found among parazoans.

What is the difference between Ostia and Asculum in poriferans?

The multiple minute pores in the poriferans are termed as “Ostia“, while a common large pore is termed as “Osculum” . Poriferans have no fixed shape and all possess an internal skeleton and a large cavity in between called “Spongocoel”. It includes members like Sycon, Spongilla, Euspongia, etc.