The Living Cell: Commentary
The Living Cell The Living Cell: Commentary In my research, I will provide scientific descriptions and definitions of cell types, and cell classes.
The current theory of cellular biology may be presented as a set of six statements: (1) all living material is made up of cells; (2) all cells are derived from previously existing cells; most cells arise by cell division, but in sexual organisms they may be formed by the fusion of sperm and egg; (3) a cell is the most elementary unit of life; (4) every cell Is bounded by a plasma membrane, an extremely thin skin operating it from the environment and from other cells; (5) all cells have strong biochemical similarities; (6) most cells are small, about 0. 01 CM (0. 0004 in) in length. (Inc. , 1992) History The word cell was Introduced by Robert Hooked in 1665. In the course of microscopic studies of cork, Hooked noticed that the material under study was made up of many “little boxes. ” Ten years later, Antonio van Leeuwenhoek, using a hand- held lens, described several tiny microscopic creatures later found to be bacteria and protozoa. Over the next 150 years, numerous Investigators, using the microscope, turned to the examination of living tissue and developed detailed descriptions of It.
The cell theory of life is a concept that was developed by scientists over a period of many years. The initial statement of the cell theory was formulated by Lorenz Oaken (1779-1851) In 1805. (Inc. , 1992) There are two classes of cells, prokaryote and the e aka rotes. Eukaryote Eukaryote are organisms with complex cells, with their genetic material gathered Into membrane nuclei. These organisms Include, animals, plants, and fungi, that are mostly multicultural, as well as other groups called protests that are unicellular.
The eukaryote share a common origin called super kingdom, empire, and domain. The structures of eukaryotic cells are much larger than prokaryote a thousand times by volume. They also have Internal membranes, mitochondria, and plastics. In most eukaryote there is also a process of sexual reproduction. Organ and evolution The origin of the eukaryotic cell was a milestone in the evolution of life. Although eukaryote use the same genetic code and metabolic processes as prokaryote, their higher level of organizational complexity has permitted the development of truly multicultural organisms.
Without eukaryote, the world would lack mammals, birds, fish, invertebrates, mushrooms, plants, and complex single-celled organisms. (Worldly. Com, 2012) Prokaryote Prokaryote include the domains, bacteria and arched. Prokaryote are single- celled organisms and are the smallest, simplest organisms. Prokaryote reproduce by binary fission which differs from mitosis in that a spindle is not utilized. Prokaryote have a single circular chromosome that may be 500 times the length of combines genes from two different individuals and thus promotes variation.
Prokaryote do not reproduce sexually. (Suny. Deed, 2012) The controller of cell activity is DNA, deoxyribonucleic acid, the material from which the chromosomes of a cell’s nucleus is formed. The nucleus of every human cell contains 46 chromosomes; each is a long, coiled molecule of DNA, and together they contain about 100,000 genes. Every gene is a tiny segment of DNA that controls a specific cell function by overriding the synthesis, or manufacture, off specific protein. Clansman, 1995) The living cell has very complex cycles of divisions, phases and so on. The one proven theory is that every living thing consists of cells that begin as molecules, cells, tissues, organs, organ systems, and complex organisms. As we watch the process of cells at work with something as simple as a small burn from a curling iron on a young girl’s neck, we observe skin cells repairing the damaged skin. The outcome of the healing process depends deeply on the temperature of the hot iron as to how much tissue mage will there be if any at all.