Assignment: use of data bases, looking at gene structure as well as give you a practical on recombinant dna technology and genomic section. About 25000 genes in the human genome. Out of the ones from above only one cell type of about 10000 of the genes are expressed. Correct expression of the gene is essential for growth and differentiation of cells. Also critical in the growth and development of all organisms and their ability to respond to their environments. Diseases are due to altered expression of one or more genes. Trying to manipulate the gene expression; by manipulating the gene potential we have the ability to prevent or reverse disease states. Can"t use dna b/c can"t be directly amplified. Despite the fact that the central dogma makes it appear that there are two steps, there are in fact many many more steps in gene expression. Gene expression steps in eucariotic cell (dna transcription rna translation protein: transcription.