The major route for endocytosis in most cells, and the best-understood, is that mediated by the molecule clathrin. This large protein assists in the formation of a coated pit on the inner surface of the plasma membrane of the cell.This pit then buds into the cell to form a coated vesicle in the cytoplasm of the cell.he major route for endocytosis in most cells, and the best-understood, is that mediated by the molecule clathrin. This large protein assists in the formation of a coated pit on the inner surface of the plasma membrane of the cell.
Sponges are extremely primitive invertebrate life so are classed under the Kingdom Animalia, they do not photosynthesise so are not plants. They are also very different to fungi and have an entirely different composition and life cycle. A sponge if passed through a sieve gradually reforms its original shape.ponges are extremely primitive invertebrate life so are classed under the Kingdom Animalia, they do not photosynthesise so are not plants. They are also very different to fungi and have an entirely different composition and life cycle. A sponge if passed through a sieve gradually reforms its original shape.
The scientific term for sponges is Porifera, which literally means pore-bearing. The surface of a sea sponge is made up of thousands of tiny pores, called ostia. These pores lead internally to a system of canals, whose main functions are collecting nutrients and oxygen, and disposing waste and carbon dioxide. sea sponge's body primarily consists of spicules and spongin. Spicules are needle shaped fiberlike structures that act as the sponge's skeleton. Spongin is a protein that helps provide body support. In some instances the spongin will combine with the spicules to provied support, in other times the spongin works alone.