Only for those groups have scientists almost completely identified all the world's species. Biologists have yet to describe many species of plants, invertebrate animals and lichens. So the number of these species known to science increases substantially every year.
The interglandular tissue is also increased in quantity, and is crowded with large round, oval, or polygonal cells, termed decidual cells. Their enlargement is due to glycogen and lipid accumulation in the cytoplasm allowing these cells to provide a rich source of nutrition for the developing embryo.rom Wikipedia, the free encyclopedia. Before the fertilized ovum reaches the uterus, the mucous membrane of the body of the uterus undergoes important changes and is then known as the decidua.
1 Cell Specialization: Normal cells have the ability to differentiate or develop into specialized cells. 2  For example, cells can develop into heart cells, brain cells, lung cells or any other cell of a specific type. 3  Cell Death: Normal cells have the ability to self destruct when they become damaged or diseased. Normal cells reproduce properly. 2  Except for sex cells, all cells of the body reproduce by mitosis. 3  Sex cells reproduce through a process called meiosis. 4  Cell Communication: Cells communicate with other cells through chemical signals. 5  These signals help normal cells to know when to reproduce and when to stop reproducing.