Why does the cell use mRNA at the ribosome instead of DNA?

History, control & amplification. Ribosomes are ancient; they contain a ribozyme and a structure largely conserved across all of life. Ribosomes may well predate the organization of genes into chromosomes and perhaps the use of DNA as genetic material. read more

Thus these spliceosomes and alternative splicing creates a number of different mRNA messages from the shared organism DNA in cells that are differentiated to perform different tasks. To clarify, an mRNA is a base complementary RNA strand of a DNA gene. read more

Why can't there be a similar chemical molecule like tRNA which can directly read from DNA and exclude the mRNA intermediate. Also is the current translation process optimal in the sense that can there be a system which does not need mRNA or a similar intermediate altogether. read more