Cells are the units that make up life. Multi-cellular organisms like humans or plants can be millions or trillions of cells. Most cells are also specialized in function. Skin cells look and do very different things from a brain neuron. A leaf cell is much different than a root cell. Specialized (i.e. differentiated) cells started … More How (plant) cells know who they are. Flowering Flowering is a killer application of the natural world. There are 300,000 extant species of flowering plants, dwarfing any other type of plant. There are only several thousand species of other types of plants (about 15,000 mosses exist today– the next most abundant group of plants). To say flowers are an evolutionary success story … More Flowering time and genetic memory.