What is the function of spongin?
Spongin, a modified type of collagen protein, forms the fibrous skeleton of most organisms among the phylum Porifera, the sponges. It is secreted by sponge cells known as spongocytes. Spongin gives a sponge its flexibility.
What is the difference between spicules and spongin?
Some spicules are formed of the mineralized substances calcium carbonate and silica, while others are made of an organic substance called spongin. Spongin skeletons were and are used as scrubbers in bathtubs, though they are fairly expensive. The ubiquitous bathtub accessory called a lufa is NOT a sponge, but a plant.
What are spicules and spongin what are its role in the Poriferan body?
Take an up-close tour through the sponge and its cells. As we’ve seen, most sponges are supported by small bone-like spicules (usually tiny pointed structures made of calcium carbonate or silica) in the mesohyl. Spicules provide support for the body of the sponge, and may also deter predation.
How is a spongin skeleton formed?
Spicules are formed by carbonates of lime or silica in the form of needle like pieces. Spongin fibres are composed of a silk-like scleroprotein. The spicules constitute major part of skeletal system, which are secreted by special mesenchymal cells called scleroblasts.
Is spongin a spicule?
Some spicules are formed of the mineralized substances calcium carbonate and silica, while others are made of an organic substance called spongin. Spongin skeletons were and are used as scrubbers in bathtubs, though they are fairly expensive.
What are spongin and spicules?
Why are spongin and spicules important to a sponge?
Spongin and spicules provide support and supports the soft body parts of the sponges. The spicules give the sponges rigidity and form to the sponges.
Is spongin a Spicule?
What are the functions of the spicules and spongin skeleton?
The mineral skeleton is formed for the most part by units called spicules, either scattered throughout the sponge or united to form fibres; spicules are classified as megascleres, which function in support, and microscleres, which function in protection and also aid in support.
What is spicules and spongin?
Does Hexactinellida have spongin?
Although the majority of sponges live in marine habitats, one family, the Spongillidae, is found in fresh water. Calcarea, Hexactinellida, Demospongiae, and Homoscleromorpha make up the four classes of sponges; each type is classified based on the presence or composition of its spicules or spongin.
Why are spongin and spicules important to sponges?
Solution : Spongin and spicules provide support and supports the soft body parts of the sponges. The spicules give the sponges rigidity and form to the sponges.
What is a pinacoderm in sponge?
The pinacoderm is the outermost layer of body cells (pinacocytes) of organisms of the phylum Porifera (sponges), equivalent to the epidermis in other animals.
What is the difference between a spongin and spicules?
Does Calcarea have spongin?
Calcareous sponges have calcium carbonate spicules and but no spongin. Most calcareous sponges are small, seldom exceeding a few centimeters. All three levels of construction – simple, compound and complex – are present among calcareous sponges. Leucosolenia has the simple level of sponge organization.
Is Euspongia a Leuconoid?
The third and most common type is the leuconoid system where the choanocytes occupy distinct chambers; examples include Euspongia and Leuconia.
What is the function of pinacoderm?
For example, epithelial-like cells called pinacocytes form the outermost body, called a pinacoderm, that serves a protective function similar that of our epidermis. Scattered among the pinacoderm are the ostia that allow entry of water into the body of the sponge.