Biologically speaking, human beings are made up of cells. Cells are single-celled organisms with no nucleus and a DNA strand (which can be passed from one generation to another). The DNA is responsible for making us who we are, but it also determines how our cells multiply, divide, and respond to external stimuli. In general, though, the DNA dictates most of what makes us what we are today.
Cells that divide quickly grow into the different types of cells found in the body. Those that divide slowly accumulate the waste material of their predecessors and become fat cells, muscle cells, or blood cells. And all three of these cell types can divide at very fast speeds, which is why some people have extremely fast metabolisms and very low fat levels, while others have low fat levels and extremely low metabolisms.
Cells can be grown inside of a culture. Typically, this is done with living cells that have been grown under laboratory conditions for several days. Cells grown in this way can then be fed nutrients or stimulated with the appropriate chemicals, and their own cellular DNA can be altered to create new cells. If the desired effects are desired, the cells are then harvested and transplanted to another location. While this may seem easy enough, it is not the same as making a cell from scratch.
Cells can also be transferred from one part of the body to another. If a tumor is removed from another part of the body, the cancerous cells can be surgically removed from the original area. After surgery, the cells can then be moved to another part of the body where they can grow. While it is possible to implant these cells through surgery, it is not an exact science, and sometimes mistakes can occur and the implant can cause the cells to divide abnormally, or spread.
Many scientists are interested in manipulating cells to produce more than the number of cells that can be found naturally. This can result in the production of a product that is desirable in one way, yet undesirable in another. There are some cells, for example, that can only produce energy when exposed to light, or chemicals. or heat. Others can actually turn themselves into fat while others can create energy through chemical reactions.
Cells have the potential to multiply in ways that were unknown in the past. Some scientists are interested in the ability of cells to multiply in ways that would allow them to create large amounts of a substance such as drugs. Others would like to create more than enough cells so that the body will have more energy than it needs or the capacity to sustain life.
Biotechnology encompasses a lot of areas of science that involve the creation of new materials, including the design of materials or plants, or the production of new materials that may otherwise be too large for the natural environment. These new materials can then be used for the purpose of making products such as food, clothes, fuel, or even fuel. Other methods of bio-engineering include the production of artificial tissues for medical purposes, or the use of materials to create electronic devices.