Here's why mRNA has to be made:

* DNA is the blueprint: DNA contains the genetic instructions for building and maintaining an organism. However, DNA is locked away safely in the nucleus of a cell. It can't leave the nucleus and directly create proteins.

* mRNA as a messenger: mRNA acts as a messenger molecule, carrying the genetic instructions from the DNA in the nucleus to the ribosomes in the cytoplasm. Ribosomes are the protein-making factories of the cell.

* Protein synthesis: At the ribosomes, mRNA's instructions are used to assemble amino acids into specific protein chains. These proteins are essential for virtually every function in the body, including building and repairing tissues, transporting molecules, and regulating chemical reactions.

In summary: mRNA is a crucial intermediary molecule that allows the genetic information stored in DNA to be translated into proteins, the workhorses of the cell.