double-labeling experiments with [ 5-3h ] uridine and [ methyl-14c ] methionine indicated that unmethylated giant heterogeneous rna larger than 45 s is processed much more slowly than the 45 s ribosomal precursor , so that relatively large amounts of fairly stable rna of the former class accumulate in the cell .
C0035553
ribosomal
C0007634
cell