Question

Eukaryotic 45S RNAcontains 3 RNAs. Identify the 3
products in order of
transcription.

Answer 1

The three rRNA products are:

• 18S rRNA
• 5.8S rRNA
• 28S rRNA

Step-by-step explanation:

• The eukaryotic 45S RNA is a combination of 3 smaller rRNA trancripts separated by RNA spacers.
• The 45 rRNA is transcribed by RNA Polymerase 1 from the gene of the same name as a whole.
• It is a pre-cursor RNA that undergoes nucleolytic cleavage by specific RNA endonucleases into the three products: an 18S, 5.8S and 28S rRNA.
• The 18S rRNA and ribosomal proteins constitute the 40S subunit of the eukaryotic ribosome.
• The 5.8S, 28S and another 5S rRNA constitute the 60S subunit.