1, b; 2, b; 3, dintrons are the regions which is splited out from the gene and not expressed in eukaryotic system,
extrons are the regions EXpressed into protein.
the negative charge is not carred by the base but the phosphate group.
Ribosomal RNA are the enzymatic RNA exist in ribosome,
there are 3 in prokaryotic system,
together with other proteins, involved in initiation and elongation, as attracting factors for tRNA binding inside the ribose, as weell as the key factors controlling the expression dosage, especially 16s in Ecoli, some expression ehancers are known to be 16s complementary element, the last point, is, by modern molecular microbiology, the reason why bacteria are classified by 16s rRNA sequencing....
bdd, 2a is correct.