What is meant by collar cell?
: a flagellated endodermal cell that lines the cavity of a sponge and has a contractile protoplasmic cup surrounding the flagellum. — called also choanocyte.
What is the function of the collar cells?
One of the main digestive cell types is the choanocyte. These cells are commonly called “ collar cells ” because they have a collar of microvilli at the cell surface that is used to trap food particles flowing through the organism.
What are Choanocytes or collar cells What is their functions?
The collar is made of many microvilli and is why these cells are also referred to as collar cells. The choanocytes carry out a variety of functions including circulation, capturing food, and assisting with reproduction. The movement of the flagellum creates water currents that aid in circulation.
What is collar in biology?
In Biology terminology a collar describes an encircling structure or bandlike marking or junction, as around the neck of an animal, or a plant base suggestive of a collar. Collar [ Botany ]
Where are collar cells located?
– Collar cells are located in the canals of the sponge within the chambers. -They beat their flagella back and forth to force water through the sponge. -The sticky collars of the collar cells pick up tiny bits of food brought in with the water.
What Spicule means?
1: a slender pointed usually hard body especially: one of the minute calcareous or siliceous bodies that support the tissue of various invertebrates (such as sponges) 2: a spikelike short-lived prominence appearing close to the chromosphere of the solar atmosphere.
What is another name for collar cells?
Choanocytes (also known as ” collar cells “) are cells that line the interior of asconoid, syconoid and leuconoid body types of sponges that contain a central flagellum, or cilium, surrounded by a collar of microvilli which are connected by a thin membrane.
What do Choanocytes do?
Choanocytes are versatile cells. Their flagella beat to create the active pumping of water through the sponge, while the collars of the choanocytes are the primary areas that nutrients are absorbed into the sponge. Furthermore, in some sponges the choanoflagellates develop into gametes.
What is meant by Gemmules?
Gemmules are internal buds found in sponges and are involved in asexual reproduction. It is an asexually reproduced mass of cells, that is capable of developing into a new organism i.e., an adult sponge.
What do Choanocytes produce?
The structure of a choanocyte is critical to its function, which is to generate a water current through the sponge and to trap and ingest food particles by phagocytosis. Note that there is a similarity in appearance between the sponge choanocyte and choanoflagellates (Protista).
Where do Choanocytes occur in each body type?
Choanocytes (“collar cells”) are present at various locations, depending on the type of sponge; however, they always line the inner portions of some space through which water flows: the spongocoel in simple sponges; canals within the body wall in more complex sponges; and chambers scattered throughout the body in the
What is Pinacoderm and Choanoderm?
Pinacoderm and choanoderm are two epithelial-like surfaces of sponges. Pinacoderm is the external skin of sponges, while choanoderm is the innermost surface of the sponges.
Why is a collar called a collar?
Word usage The Oxford English Dictionary traces collar in its modern meaning to c. 1300, when collars served as neck-protecting armour.
What is collar region?
The collar region of the leaf blade is most useful for identifying grasses before they flower (flower heads may provide a more obvious means for identification). The collar marks the junction between the blade and the outer sheath on the outside of the leaf. It consists of the leaf blade, sheath, ligule, and auricles.
What does Blue Collar mean?
Blue – collar worker refers to workers who engage in hard manual labor, typically agriculture, manufacturing, construction, mining, or maintenance. If the reference to a blue – collar job does not point to these types of work, it might imply another physically exhausting task.