Food is the most vital product of the agriculture sector. But there other non-food products critical to the economy generated in this multi-billion dollar industry, including cotton, wool and tobacco. Prior to the Great Depression, government subsidies to the agriculture sector were relatively limited.
Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, that all cells come from preexisting cells, and that all cells contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.
Actually, both plant and animal cells come in many different shapes and sizes depending on the cell's particular function within the organism (see attached). For example, neurons at the base of your spinal cord can extend all the way to the tip of your big toe (a single cell that's 3+ feet long!).owever, all plant cells have cell walls, which animal cells never do, and the presence of cell walls is what gives plant cells their characteristic block-like shape, and the absence is why animal cells, in the lack of other factors, do not.