how many cell layers compose a porifera

Phylum Porifera - Primitive multicellular animals with cellular grade of organisation. Free living aquatic, mostly marine, sedentary forms either solitary or colonial. Body with a large number of incurrent pores called ostia leading into a spongocoel through a system of canals, Spongocoel..

All living organisms are composed of structural and functional units called cells. The body of a living organism may be composed of a single cell - as in unicellular organisms or many cells - as in multicellular organisms. The number of c..

All living organisms are composed of structural and functional units called cells. The body of a living organism may be composed of a single cell - as in unicellular organisms or many cells - as in multicellular organisms. The number of cellsh..

A lose gelatinous sheath called slime layer is usually deposited around the bacterial cell wall. It is usually composed of polysaccharides. In some bacteria, the slime layer becomes thick due to the presence of some nitrogen compounds and forms a capsule. A c..

It consists of the rods and cones. The rods and cones are the photoreceptor cells that contain the pigments that trap the incident light rays and convert their energy into action potentials. These action potentials are then transmitted as nervous impulses. The pigments are present on..

The simplest multicellular animals. The cells are loosely held together and do not form tissues. Ostia (pores) are present all over the body, with a single large opening on top called osculu..

Features of Porifera..

A cell wall surrounds the plasma membrane in all plant cells. It is a porous covering of about 0.1 milli microns to 10 milli microns in size. The cell wall is chiefly composed of insoluble polysaccharides. The most common constituent is cellulose. Certain oth..

This layer comprises of the ganglions. The dendrites of the ganglions at one end are in contact with the bipolar nerve cells and at the other end, with the optic nerve axon..

A lose gelatinous sheath called slime layer is usually deposited around the bacterial cell wall. It is usually composed of polysaccharides. In some bacteria, the slime layer becomes thick due to the presence of some nitrogen compounds and forms a capsul..