Match one of the following terms with each of the descriptions given below. Terms: (1) sigma (s) factor; (2) poly(A) tail; (3) TATAAT; (4) exons; (5) TATAAAA; (6) RNA polymerase III; (7) intron; (8) RNA polymerase II; (9) heterogeneous nuclear RNA (hnRNA); (10) snRNA; (11) RNA polymerase I; (12) TTGACA; (13) GGCCAATCT (CAAT box).
Descriptions:
(a) Intervening sequence found in many eukaryotic genes.

(b) A conserved nucleotide sequence (-30) in eukaryotic promoters involved in the initiation of transcription.

(c) Small RNA molecules that are located in the nuclei of eukaryotic cells, most as components of the spliceosome, that participate in the excision of introns from nuclear gene transcripts.

(d) A sequence (-10) in the nontemplate strand of the promoter of E. coli that facilitates the localized unwinding of DNA when complexed with RNA polymerase.

(e) The RNA polymerase in the nucleus that catalyzes the synthesis of all rRNAs except for the small 5S rRNA.

(f) The subunit of prokaryotic RNA polymerase that is responsible for the initiation of transcription at promoters.

(g) An E. coli promoter sequence located 35 nucleotides upstream from the transcription-initiation site; it serves as a recognition site for the sigma factor.

(h) The RNA polymerase in the nucleus that catalyzes the synthesis of the transfer RNA molecules and small nuclear RNAs. (i) A polyadenosine tract 20–200 nucleotides long that is added to the 3′ end of most eukaryotic messenger RNAs.
(j) The RNA polymerase that transcribes nuclear genes that encode proteins.

(k) A conserved sequence in the nontemplate strand of eukaryotic promoters that is located about 80 nucleotides upstream from the transcription start site.

(l) Segments of an eukaryotic gene that correspond to the sequences in the final processed RNA transcript of the gene. 

(m) The population of primary transcripts in the nucleus of a eukaryotic cell.