1 Describe the three layers of the sponge body plan. cellular
Epidermius- outercovering then cellular inside lined with choanocytes then mesohy jelly layer in between the too noncelluar
Sponges consist of a body wall of 3 layers (2 cell layers surrounding a jellylike mesohyl layer). The outer body wall is composed o
What is the purpose of the atria (spongocoel) in a sponge?
These cavities are necessary so that all the cells can be in contact with the water which allows the diffusion of gases and nutrients across each cell membrane. Water is kept constantly flowing through a sponge. It enters the sponge through hollow cells c
Describe the path that water takes through a sponge
It enters the sponge through hollow cells called pore cells. It moves through the atria. Water exits the sponge through one or more large openings called oscula (singular is osculum).
Describe the structures of a choanocyte
The outer body wall is composed of epidermal cells which serve as covering for the sponge. Interspersed among these epidermal cells are pore cells (porocytes). These are hollow cells which extend across the entire body wall. Water enters the sponge throug
How is the current created that brings water (and food) into the sponge?
They whip their flagella constantly to create a current which pulls water into the sponge through the pore cells.
What is mesohyl?
Between these 2 cell layers is a noncellular jellylike layer called the mesohyl. Although it is not made of cells, there are wandering cells in the mesohyl called amoebocytes. These amoebocytes are responsible for carrying nutrients from the choanocytes t
What are the three classes of sponge and what is the skeleton of each made of?
Class Calcarea includes sponges which have calcium carbonate spicules. Class Hexactinellida are sponges which have fused silica spicules (Venus' flower basket). Class Demospongiae includes sponges with a support of spongin mesh. These are the commercial s
What are the three levels of folding in sponge from least to most?
Sponges may show one of 3 possible levels of folding. Asconoid have no folds. Synconoid sponges have some folds. Leuconoid sponges have complex folds.
What cell is responsible for transporting nutrients and wastes in a sponge
These amoebocytes are responsible for carrying nutrients from the choanocytes to other cells and excreting wastes.
What is the skeleton of a member of the class Hexactinellida composed of?
Class Hexactinellida are sponges which have fused silica spicules
How are sponges different from other filter feeders?
Sponges produce their own current using its flagella
What cell is responsible for secreting spicules in a sponge?
Ambeocytes (gamete formation too)