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.
No representative specimens available in class. B. PRINCIPAL FEATURES The sponges are the first metazoans (multicellular animals) that we will study. The principal features of phylum Porifera are listed below. 1. While some sponges are radially symmetrical, the majority of sponges are asymmetrical in body form.