PLEASE HELP WILL GIVE BRAINELIST Please summarize to answer, how do cells undergo differentiation to form the numerous types of cells in the body?
Cellular differentiation, or simply cell differentiation, is the process through which a cell undergoes changes in gene expression to become a more specific type of cell. The process of cell differentiation allows multi-cellular organisms to create uniquely functional cell trt42ypes and body plans. The process of cell differentiation is driven by genetics, and their interaction with the environment.
All organisms begin from a single cell. This single cell carries the DNA coding for all the proteins the adult organism will use. However, if this cell expressed all of these proteins at once it would not be functional. This cell must divide repeatedly, and the cells must begin the process of cell differentiation as they divide. The cell lines begin to emerge, and the cells get more and more specific. Eventually, an entire organism is formed with hundreds of different cell types from this process of cell differentiation.
The original mass of cells, which have not undergone differentiation, are known as stem cells. Unlike normal cell division, which creates two identical daughter cells, the division of stem cells is asymmetric cell division. In this case, one of the cells remains identical to the parent stem cell. In the other cell, chemical triggers activate the process of cell differentiation, and the cell will start to express the DNA of a specific cell type. Stem cells which can differentiate into entire organisms are known as embryonic stem cells and are said to be totipotent.
By contrast, the body also has many cells which are only pluripotent. These cells have already undergone some cell differentiation. These stem cells can only divide into a narrow range of cell types. Bone marrow, for instance, contains somatic stem cells which can only become red blood cells. These cells are necessary for the constant replenishment of blood cells, which are mostly inactive besides their oxygen-carrying ability.
Cell Differentiation Examples
In Animals
After the process of fertilization in animals, a single-celled organism called the zygote is formed. The zygote is totipotent, and will eventually become an entire organism. Even the largest animal on Earth, the blue whale, starts as a single cell. The complex tissues and organ systems, which are completely different in their form and function, all come from the zygote. The process of cell differentiation starts early within the organism. By the time the gastrula has formed, the cells have already started expressing various portions of the DNA.
These changes drive the first folding processes within the embryo. As the tissues continue to form, some cells begin releasing hormones, or chemical triggers which signal various cells to react. Hormone signals direct the expression of DNA in various body parts, which drives their cell differentiation further. In humans it only takes a little over a month for a rudimentary heart and circulatory system to form.
As the systems continue to form, many of the stem cells lose their totipotency, themselves undergoing cell differentiation. This allows for faster production of specialized cells, which the growing organism needs to sustain its growth and enter the world with success. Through cell differentiation, tissues as different as brain tissue and muscle are formed from the same single cell.