in which crucial step of gene expression does the ribosome play a major role: transcription or translation?

Translation is the step in which ribosome play a major role.

Answer: Option 2.

Explanation:

Ribosomes' capacity is to make proteins. They do this in a procedure known as translation, which includes taking directions encoded in detachment ribonucleic corrosive (mRNA) and utilizing these to gather proteins from amino acids.

The ribosome has a small and a large sub unit and is a complex molecule composed of several ribosomal RNA molecules and a number of proteins ... Next, the large ribosomal sub unit binds to form the complete initiation complex. During the elongation stage, the ribosome continues to translate each codon in turn.