REMOVING floor-to-ceiling walls at the top of a stairway can turn an upstairs hallway or room into a light and airy landing and also bring increased light and openness to the stairwell. For safety, the floor surrounding the stairway must be partly enclosed. One solution is to install a railing around the opening.
A sponge is a member of the phylum Porifera. It is a simple animal with many cells, but no mouth, muscles, heart or brain. It is sessile: it cannot move from place to place the way most other animals can. A sponge is an animal that grows in one spot like most plants do.Nevertheless, sponges are quite successful. sponge is a member of the phylum Porifera. It is a simple animal with many cells, but no mouth, muscles, heart or brain. It is sessile: it cannot move from place to place the way most other animals can. A sponge is an animal that grows in one spot like most plants do. Nevertheless, sponges are quite successful.
Sponges are built up from relatively few cell types, the main ones being choanocytes, pinacocytes, amoebocytes and lophocytes. Pinacocytes, these form much of the epidermis of sponges and are as close as a sponge gets to having a tissue.Generally they cover the exterior and some interior surfaces. sponge is a simple organism that is easy to describe. A sponge is a sedentary, filter-feeding metazoan which has a single layer of flagellated cells that drive a unidirectional current of water through its body. such a brief description though does not do them justice.