What are the three main types of RNA?

The three main types of RNA are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

mRNA serves as the template for protein synthesis, carrying genetic information from DNA to the ribosome, where proteins are produced. tRNA plays a crucial role in translation by transporting the appropriate amino acids to the ribosome, ensuring that proteins are assembled correctly based on the sequence of the mRNA. rRNA, on the other hand, is a structural component of ribosomes, which are essential for protein synthesis, facilitating the binding of mRNA and the tRNAs.

This answer identifies the key roles of each type of RNA in the process of gene expression and protein synthesis, highlighting their importance in cellular function. Other options contain types of RNA that are involved in different processes, such as small interfering RNA (siRNA) or small nuclear RNA (snRNA), which do not represent the primary categories of RNA central to the processes of transcription and translation.