The 2024 Nobel Prize in Physiology or Medicine was awarded to Victor Ambros and Gary Ruvkun for discovering :

The 2024 Nobel Prize in Physiology or Medicine was awarded jointly to Victor Ambros and Gary Ruvkun for the discovery of microRNAs (miRNAs) and their role in post-transcriptional gene regulation. Their work, published in 1993 (Ambros on the lin-4 gene and Ruvkun on the lin-14 gene in the roundworm C. elegans), showed that a tiny RNA molecule does not code for a protein but binds to the messenger RNA of a target gene and blocks its translation. This was a completely new layer of gene control, and it was later found that microRNAs are present in almost all multicellular animals and plants and regulate a large share of human genes.

Why are the other options wrong? Ribosomal RNA (rRNA) is a structural and catalytic component of ribosomes, where protein synthesis takes place. Transfer RNA (tRNA) carries amino acids to the ribosome and reads the codons of mRNA with its anticodon. Messenger RNA (mRNA) carries the genetic code copied from DNA to the ribosome and was discovered much earlier, in the 1960s, through the work of Jacob, Monod and others. All three are well-known, basic RNA types, which is why students often confuse them, but the 2024 prize specifically recognised the small regulatory RNAs.

For revision, remember that miRNAs are about 21–25 nucleotides long, are transcribed as longer precursors that are processed by the enzymes Drosha and Dicer, and act by silencing or degrading target mRNAs. Their role in development, cancer and other diseases is an important area of current research and biotechnology.