Introns and exons are nucleotide sequences found within genes, primarily in eukaryotic organisms.

• Introns are non-coding sequences that are transcribed into precursor RNA but are removed during RNA splicing before the formation of mature messenger RNA (mRNA). They do not code for proteins and are considered intervening sequences that interrupt the linear coding sequence of a gene. Introns are usually less conserved and can vary over time. They are found in eukaryotes and are removed in the nucleus before mRNA moves to the cytoplasm for translation

• Exons are coding sequences that remain in the mature mRNA after splicing and are translated into proteins. They are conserved sequences that represent the expressed regions of a gene. Exons are joined together covalently during RNA processing to form the continuous coding sequence of the mRNA that directs protein synthesis

In summary, genes are composed of alternating introns and exons, where introns are removed during RNA processing, and exons are retained to code for proteins. This arrangement allows for complex regulation and diversity in gene expression