Here's a breakdown:

* mRNA: Carries the genetic code from DNA in the nucleus to the ribosomes in the cytoplasm.

* Ribosomes: Cellular organelles responsible for protein synthesis. They read the mRNA code and use it to assemble amino acids into proteins.

The process:

1. mRNA is transcribed from DNA in the nucleus.

2. mRNA travels out of the nucleus and into the cytoplasm.

3. In the cytoplasm, mRNA binds to a ribosome.

4. The ribosome "reads" the mRNA code, one codon (three-nucleotide sequence) at a time.

5. For each codon, the ribosome recruits the corresponding tRNA (transfer RNA), which carries a specific amino acid.

6. The ribosome links the amino acids together, forming a polypeptide chain.

7. The polypeptide chain folds into a functional protein.

So, the attachment of mRNA to ribosomes is the crucial first step in protein synthesis.