Every cell in the body has a full complement of all genes, however each cell type reads only certain genes. For example, both white blood cells and liver cells have genes for making digestive enzymes but they do not read them. how is this possible??? I have no idea?
I googled cell differentiation and got a fairly good result from Wikkipedia.
i don't know either my science teacher mr.radeke has know clue either!
Cell differentiation is the process by which cells acquire specialized functions and structures as they develop into specific cell types in multi-cellular organisms. It allows different cell types to have distinct functions and characteristics in the body. The ability of cells to read only certain genes is controlled by a mechanism called gene regulation.
Gene regulation involves the activation or repression of specific genes in response to signals from the cell's environment or developmental stage. This regulation is achieved through a complex network of molecular interactions, which can occur at multiple levels.
One of the primary mechanisms of gene regulation is the binding of specific proteins called transcription factors to the regulatory regions of genes. These regulatory regions are typically located near the genes themselves and contain DNA sequences that act as switches to control gene expression. When transcription factors bind to these regulatory regions, they can either promote or inhibit the transcription of the gene, determining whether it is read or not.
In the example you mentioned, white blood cells and liver cells have the same genes for making digestive enzymes, but they do not read them. This is because the regulatory regions of those genes in these specific cell types do not receive the appropriate signals or do not possess the necessary transcription factors to activate their expression. As a result, these genes remain dormant or repressed in those cell types.
The precise control of gene regulation during cell differentiation allows for the specialization of cell types and ensures that each cell type only expresses the genes necessary for its specific function. This process is crucial for the proper functioning of organs and tissues in the body.