Question

what are introns and exons?


class 12th CBSE Biology sample paper

Answer 1

In most eukaryotic genes, coding regions (exons) are interrupted by noncoding regions (introns). During transcription, the entire gene is copied into a pre-mRNA, which includes exons and introns. During the process of RNA splicing, introns are removed and exons joined to form a contiguous coding sequence.

Answer 2

In Eukaryotes the monocistornic structural genes have interrupted coding sequence the gene in eukaryotes are split.

The coding or expressed sequence are defined as Exons

Exons are said to be those sequence that appear in mature or processed mRNA.

The exons are interrupted by Introns.

These intervening sequences (introns) do  not appear in mature or processed RNA.

the RNA with both intron and exons  (or immature RNA ) after transcription is also known as hnRNA. (hetero-nuclear RNA).