Final answer:
Small nuclear RNAs (snRNAs) are false to be essential for the formation of a functional ribosome; they are involved in mRNA splicing. Ribosomes are primarily made from rRNA and proteins, with rRNA playing a critical role in protein synthesis on the ribosome.
Step-by-step explanation:
The statement that small nuclear RNAs (snRNAs) such as U1 and U2 are essential for the formation of a functional ribosome is false. snRNAs are indeed involved in the splicing of pre-mRNA by forming complexes known as small nuclear ribonucleoproteins (snRNPs) but are not directly involved in the formation of the ribosome. Ribosomes are primarily composed of ribosomal RNA (rRNA) and proteins, and it is rRNA that plays a critical role in protein synthesis by ensuring the proper alignment of mRNA on the ribosome during translation and catalyzing the formation of peptide bonds between amino acids. tRNA, or transfer RNA, acts as the adaptor molecule that brings amino acids to the ribosome, according to the genetic code carried by mRNA. Each tRNA has an anticodon that pairs with a complementary codon on the mRNA, allowing for the correct amino acid to be inserted into the growing polypeptide chain.