Final answer:
The four bases of RNA are adenine (A), guanine (G), cytosine (C), and uracil (U), with uracil replacing thymine from DNA. These nitrogenous bases form the genetic code used for protein synthesis and other processes in cells. RNA is primarily single-stranded with a ribose sugar backbone.
Step-by-step explanation:
These nitrogenous bases form the genetic alphabet that RNA uses to carry genetic information, which is crucial for protein synthesis and other cellular processes. The bases are termed 'nitrogenous' because they contain nitrogen atoms. The purines, adenine and guanine, have two carbon-nitrogen rings and are larger than the pyrimidines, cytosine, and uracil, which only have one ring. RNA is predominantly single-stranded and its backbone is made of ribose sugar units linked by phosphodiester bonds. In RNA synthesis, the sequence of the RNA molecule is complementary to the DNA template from which it is transcribed. Among different types of RNA, messenger RNA (mRNA) is noteworthy as it carries the genetic message from DNA to the ribosomes, where proteins are synthesized. The other major types of RNA, including ribosomal RNA (rRNA), transfer RNA (tRNA), and microRNA (miRNA), play essential roles in various other cellular activities.