What are ribosomes primarily composed of?

Ribosomes are primarily composed of RNA and protein. This composition is integral to their function in the cell. Ribosomal RNA (rRNA) serves both structural and catalytic roles, allowing ribosomes to facilitate the process of translation, which is the synthesis of proteins from amino acids based on the sequence encoded in messenger RNA (mRNA). The protein components of ribosomes provide additional structural support and contribute to the ribosome's overall functionality, ensuring that it can effectively assemble the components necessary for protein synthesis.

This combination of components is crucial, as rRNA forms the core of ribosome structure while proteins help stabilize that structure and support catalytic activities. Other answer options miss the mark because they either include incorrect components or omit key elements necessary for ribosome formation. For instance, DNA is not part of ribosomes, nor are carbohydrates a significant component in their structure. Thus, the only accurate representation of ribosome composition is RNA and protein.