Exons are termed as nucleic acid coding sequences, which are present in mRNA. Introns are the non-coding sequences present in the DNA, which are removed by RNA splicing before translation. The intron sequences change frequently with time, whereas, the exon sequences are highly conserved.
Read on to explore the major differences between exons and introns.
Difference between Introns and Exons
Following are the important difference between introns and exons:
|Found in Eukaryotes only||Found in both prokaryotes and eukaryotes|
|Non-coding areas of the DNA||Coding areas of the DNA|
|Introns are the non-coding part of hnRNA, which are removed before translation by RNA splicing to form mRNA||Exons are the nucleotide sequence in mRNA, which codes for proteins|
|The sequence of the introns changes frequently over time. In other words, they are less conserved||Exons are highly conserved|
|DNA bases found in between exons||DNA bases that are translated to proteins|
|Introns are removed in the nucleus before the mRNA moves to the cytoplasm||Mature mRNA contains exons and moves to the cytoplasm from the nucleus|
Also Read: RNA Interference
What are Introns?
Introns are intervening sequences between two exons found in eukaryotes. They do not directly code for proteins. They are removed before the mRNA forms proteins. Therefore, these introns undergo the process of splicing.
Introns are the non-coding parts of the nucleotides and are not highly conserved. therefore, it is essential to remove introns to prevent the formation of incorrect proteins.
What are Exons?
Exons are the coding sequences that code for amino acid sequence of the protein. The exons are transcribed into mature mRNA after post-transcriptional modification. These are highly conserved sequences, i.e., they do not change frequently with time.
From the listed difference, we can conclude that the main difference between exons and introns is their function in the genome.