Phylum Porifera Flashcards
Animals in Subkingdom Parazoan represent the simplest of all within the invertebrata, animals that do not possess a cranium or vertebral column. In fact, this subkingdom of animals includes only one phylum ____
Porifera
Since water is vital to sponges for excretion, feeding, and gas exchange, their body structure facilitates the movement of water through the sponge. Structures such as ___, ____, and _____ enable water to move through nearly all body cells.
canals, chambers, and cavities
The morphology of the simplest sponges takes the shape of a cylinder with a large central cavity, the ____, occupying the inside of the cylinder
spongocoel
Water entering the spongocoel is extruded via a large common opening called the _____.
osculum
Pinacocytes, which are epithelial-like cells, form the outermost layer of sponges and enclose a jelly-like substance called ___
mesohyl
___ consists of a collagen-like gel with suspended cells that perform various functions. This gel-like consistency acts like an endoskeleton and maintains the tubular morphology of sponges
Mesohyl
In addition to the osculum, sponges have multiple pores called ___ on their bodies that allow water to enter the sponge.
ostia
In some sponges, ostia are formed by ____, single tube-shaped cells that act as valves to regulate the flow of water into the spongocoel
porocytes
Its function is to generate a water current through the sponge and to trap and ingest food particles by phagocytosis
Choanocytes
The second crucial cells in sponges are called ____, named for the fact that they move throughout the mesohyl in an amoeba-like fashion.
Functions:
-delivering nutrients from choanocytes to other cells within the sponge, giving rise to eggs for sexual reproduction -delivering phagocytized sperm from choanocytes to eggs, and differentiating into more-specific cell types.
Amoebocytes / Archaeocytes
The presence and composition of spicules/spongin are the differentiating characteristics of the three classes of sponges.
Identify the Class:
- Class ____ - contains calcium carbonate spicules and no spongin
- Class _____ - contains six-rayed siliceous spicules and no spongin
- Class ____ - contains spongin and may or may not have spicules; if present, those spicules are siliceous.
- Class Calcarea
- Class Hexactinellida
- Class Demospongia
In some sponges, ____ secrete small spicules into the mesohyl, which are composed of either calcium carbonate or silica, depending on the type of sponge. These spicules serve to provide additional stiffness to the body of the sponge.
sclerocytes
[ TRUE OR FALSE]
i. Choanocytes (“collar cells”) - always line the inner portions of some space through which water flows
ii. Whereas pinacocytes line the outside of the sponge
both statement are true
