Question

A eukaryotic ribosome contains four different rRNA molecules and ∼82 different proteins. Why does a cell contain many more copies of the rRNA genes than the ribosomal protein genes?

Short answer

Because the proportional synthesis of rRNA and protein is required for the production of ribosomes, a cell contains many more copies of the rRNA genes than the ribosomal protein genes.

Step-by-step solution

Ribosomal RNA

The most prevalent cellular RNA species, ribosomal RNAs, have evolved to serve as the catalytic, organisational, and regulatory core of protein production in all cells. These RNAs make up the majority of the ribosome, which is a big RNA-protein particle with two subunits that decode messenger RNAs and manufacture polypeptides from them. The 60S subunit and the smaller 40S subunit combined comprise roughly 80 proteins articulated around highly modified ribosomal RNAs in the mature 80S eukaryotic ribosome (rRNAs).

Explanation

Four separate RNA molecules and 82 different proteins make up a eukaryotic ribosome. The RNA gene is transcribed into a single RNA molecule, which is integrated into the body on its own.

The transcription of the gene by ribosomal proteins results in mRNA, which can be translated numerous times to make multiple copies of the matching protein. Because the balanced synthesis of rRNA and protein is essential for the construction of ribosomes, it is important to have many more copies of the rRNA gene than the ribosomal protein genes.