Question

What are introns and exons ? What ensures a linear arrangement of amino acids although the genes are discontinuous?

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. Hence removal of introns during splicing ensures continuous arrangement of genes that are expressed (i.e. exons). This is necessary so that translation of amino acids takes place in a linear manner without any gaps as genetic codes are read in a continuous manner during translation.