| Parameters | Introns | Exons |
|---|
| Definition | Non-coding DNA sequences inside a gene are eliminated during the maturation of the RNA product by RNA splicing. | Exons are DNA sequences that code for proteins and require the required codons or information for protein synthesis. |
| Type of sequence | Non-coding sequences that do not code for any protein are known as introns. | Exons are protein-coding sequences that are responsible for the production of certain proteins. |
| Location in the DNA | In a DNA sequence, introns are found between two exons. | Exons are protein-coding sequences that are found between two introns or between untranslated regions. |
| Distribution | Only present in eukaryotic genomes. | Present in both eukaryotic and prokaryotic genomes. |
| Location in the cell | After being spliced out of the mRNA transcript during RNA processing, introns remain in the nucleus. | After the mature mRNAs are generated, exons exit the nucleus and travel to the cytoplasm. |
| Present in | Introns can be found in DNA and mRNA transcripts, although they are not seen in mature mRNAs. | DNA, mRNA transcripts, and mature RNAs all contain exons. |
| Conserved | Intron sequences are nearly identical to exon sequences in terms of conservation. The process of exonization may turn some introns into exons. | Exon sequences are well conserved. |
| Involved | Introns are not involved in protein synthesis. | Exons are involved in protein synthesis. |
| Quantity | The nuclear genome has more introns than exons. | Exons make up a smaller proportion of the nuclear genome than introns. |
| Human genome | Introns make up 24% of the human genome. | Exons account for 1% of the human genome. |
| Alternative splicing | Alternative splicing is used to eliminate introns. | After alternative splicing, two or more exons are linked. |
| Novel genes formation | Short non-coding sections of introns may grow into real functioning genes through a continual evolutionary process, resulting in novel genes. | Exons can be arranged in a variety of ways, resulting in distinct sequences that code for different proteins. |