The coding sequences that appear in mature or processed RNA are called as:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Exons
In eukaryotes the structural gene is split. Its coding or expressed sequences are the exons, and they are interrupted by non-coding introns. The primary RNA is spliced: the introns are removed and the exons are joined.
(1) Introns — Incorrect. These are the intervening sequences. They are cut out during splicing, so they do not appear in the mature RNA.
(2) Exons — Correct. They are the sequences that stay in the mature or processed RNA.
(3) Spliced DNA — Incorrect. This is not the name of any sequence. Splicing is done on the RNA, not on the DNA.
(4) Cistrons — Incorrect. A cistron is a segment of DNA that codes for one polypeptide. It is a unit of the gene, not the name for the sequences found in mature RNA.
Note: A similar question was also asked in CUET (UG) 2026 on 18-05-2026 (Slot 1).
NCERT Extract:
Transcription Unit and the Gene – “… In eukaryotes, the monocistronic structural genes have interrupted coding sequences – the genes in eukaryotes are split. The coding sequences or expressed sequences are defined as exons. Exons are said to be those sequence that appear in mature or processed RNA.”