Briefly explain Gene Expression and how early cell differs a

Briefly explain Gene Expression, and how early cell differs and how/why genes turn on and off later in life? Please be as thorough as possible.

Solution

Gene expression: it is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as transfer RNA or small nuclear RNA genes, the product is a functional RNA. The process of gene expression is used by all known life eukaryotes , prokaryotes , and utilized by viruses to generate the macromolecular machinery for life.Several steps in the gene expression process may be modulated, including the transcription, RNA splicing, translation, and post-translational modification of a protein. Gene regulation gives the cell control over structure and function, and is the basis for cellular differentiation, morphogenesis and the versatility and adaptability of any organism. Gene regulation may also serve as a substrate for evolutionary change, since control of the timing, location, and amount of gene expression can have a profound effect on the functions of the gene in a cell or in a multicellular organism.In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, i.e. observable trait. The genetic code stored in DNA is \"interpreted\" by gene expression, and the properties of the expression give rise to the organism\'s phenotype. Such phenotypes are often expressed by the synthesis of proteins that control the organism\'s shape, or that act as enzymes catalysing specific metabolic pathways characterising the organism. Regulation of gene expression is thus critical to an organism\'s development.

The Tryptophan Repressor Is a Simple Switch That Turns Genes On and Off in .The Tryptophan Repressor Is a Simple Switch That Turns Genes On and Off in .Switching the tryptophan genes on and off. If the level of tryptophan inside the cell is low, RNA polymerase binds to the promoter and transcribes the five genes of the tryptophan (trp) operon. If the level of tryptophan is high, however, the tryptophanf the level of tryptophan inside the cell is low, RNA polymerase binds to the promoter and transcribes the five genes of the tryptophan (trp) operon. If the level of tryptophan is high, however, the tryptophan repressor is activated to bind to the operator, where it blocks the binding of RNA polymerase to the promoter. Whenever the level of intracellular tryptophan drops, the repressor releases its tryptophan and becomes inactive, allowing the polymerase to begin transcribing these genes. The promoter includes two key blocks of DNA sequence information