What is the primary role of ribosomal RNA (rRNA) in cells?

The primary role of ribosomal RNA (rRNA) in cells is to form the structure of ribosomes. Ribosomes are complex molecular machines that play a critical role in protein synthesis, and rRNA is a central component of their structure. It provides a scaffold for the assembly of ribosomal proteins and helps coordinate the interactions between rRNA, mRNA, and tRNA during translation. This structural role is essential because it enables ribosomes to carry out their function of translating the genetic code into proteins efficiently.

Other choices do not accurately describe the role of rRNA. For instance, while storing genetic material is a function of DNA rather than rRNA, rRNA does not transport ribonucleotides nor encapsulate DNA, as those roles belong to other cellular molecules and structures. This clarity highlights why the role of rRNA is fundamentally tied to structural integrity and function within the ribosome.