Final answer:
The large subunits of eukaryotic ribosomes contain the 28s, 5.8s, and 5s rRNAs, with the 5s rRNA added during the initial assembly in the nucleolus.
Step-by-step explanation:
The rRNAs found in the large subunits of eukaryotic ribosomes are 28S, 5.8S, and 5S rRNA. Specifically, the large 60S subunit contains the 28s rRNA, 5.8s rRNA, and 5s rRNA. In contrast, the 18s rRNA is a component of the smaller 40S subunit. During protein synthesis, ribosomes play a key role by assembling amino acids into proteins. These ribosomes are made up of two subunits, each containing distinct rRNAs and proteins essential for their function. The 5S rRNA is added to the nascent large ribosomal subunit in the nucleolus, and after the processing of the 45S rRNA, the mature subunits exit to the cytoplasm where they participate in protein synthesis.