Difference Wiki

Introns vs. Exons: What's the Difference?

Edited by Huma Saeed || By Sumera Saeed || Updated on October 28, 2023
Introns are non-coding DNA sequences within genes, removed before translation, whereas exons are coding sequences that remain in mRNA and are translated into proteins.

Key Differences

Introns and exons are fundamental components of gene structure in many organisms. Introns are intervening sequences that are transcribed into RNA but are not translated into protein. These segments are removed from the precursor mRNA during processing. Exons, on the other hand, are the portions of the gene that remain in the mRNA and are translated into proteins. Both introns and exons are initially transcribed from DNA into RNA.
Sumera Saeed
Oct 27, 2023
The roles of introns and exons are markedly different in gene expression. Introns often contain regulatory elements that can influence gene expression, but they are not directly involved in coding for proteins. Conversely, exons contain the actual coding sequences for proteins. The arrangement of exons within a gene determines the final structure of the protein produced.
Sumera Saeed
Oct 27, 2023
During mRNA processing, introns and exons undergo significant transformations. Introns are spliced out of the pre-mRNA molecule in a process called RNA splicing. This leaves only the exons, which are then joined together to form the mature mRNA. This process highlights the distinct roles of introns and exons in mRNA maturation.
Sumera Saeed
Oct 27, 2023
Finally, introns and exons contribute differently to genetic diversity. Introns can allow for alternative splicing, leading to the production of multiple protein variants from a single gene. Exons, being the actual coding sequences, directly determine the primary structure of proteins. Thus, both introns and exons are crucial, but in different aspects of gene function and regulation.
Sumera Saeed
Oct 27, 2023

Comparison Chart

Function

Non-coding sequences, removed before translation
Coding sequences, remain in mRNA
Sumera Saeed
Oct 27, 2023
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Role in Gene Expression

Often contain regulatory elements, not translated
Contain coding sequences for proteins
Sumera Saeed
Oct 27, 2023

During mRNA Processing

Spliced out of pre-mRNA
Joined together to form mature mRNA
Sumera Saeed
Oct 27, 2023

Contribution to Diversity

Allow for alternative splicing, multiple protein variants
Determine primary structure of proteins
Harlon Moss
Oct 27, 2023

Location in Gene

Intervening sequences between exons
Sequences that are conserved in mRNA
Sumera Saeed
Oct 27, 2023

Introns and Exons Definitions

Introns

Introns are spliced out of pre-mRNA.
Introns must be spliced to form mature mRNA.
Sara Rehman
Oct 27, 2023
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Exons

Exons determine protein structure.
Mutations in an exon altered the protein's function.
Sumera Saeed
Oct 27, 2023

Introns

Introns allow for alternative splicing.
The presence of multiple introns led to several protein variants.
Harlon Moss
Oct 27, 2023

Exons

Exons are coding sequences in DNA.
The exon encoded an essential protein segment.
Huma Saeed
Oct 27, 2023

Introns

Introns act as intervening sequences in DNA.
Introns separate exons in the gene sequence.
Janet White
Oct 27, 2023

Exons

Exons are transcribed and translated.
The gene's exons were critical for protein synthesis.
Harlon Moss
Oct 27, 2023

Introns

Introns are non-coding segments within genes.
The intron was removed during RNA processing.
Huma Saeed
Oct 27, 2023

Exons

Exons remain in mRNA after processing.
The mRNA consisted of joined exons.
Sumera Saeed
Oct 27, 2023

Introns

Introns can regulate gene expression.
An intron contained elements influencing gene activity.
Sara Rehman
Oct 27, 2023

Exons

Exons are joined post-intron removal.
Exons were spliced together after intron excision.
Sumera Saeed
Oct 27, 2023

Introns

A segment of a gene situated between exons that is removed before translation of messenger RNA and does not function in coding for protein synthesis.
Sumera Saeed
Apr 20, 2020

Exons

A nucleotide sequence that is found in a gene, codes information for protein synthesis, and is transcribed to messenger RNA.
Sumera Saeed
Apr 20, 2020

Introns

Plural of intron
Sumera Saeed
Apr 20, 2020

Exons

Plural of exon
Sumera Saeed
Apr 20, 2020

FAQs

What are exons?

Exons are coding sequences in genes that remain in mRNA and are translated into proteins.
Huma Saeed
Oct 27, 2023

Do all genes have introns and exons?

Many eukaryotic genes have introns and exons, but some genes and most prokaryotic genes do not.
Sumera Saeed
Oct 27, 2023

What are introns?

Introns are non-coding sequences in genes, removed from mRNA before translation.
Sumera Saeed
Oct 27, 2023

How are introns removed?

Introns are removed from pre-mRNA through a process called RNA splicing.
Sumera Saeed
Oct 27, 2023

Can introns be reused after splicing?

Once spliced out, introns are usually degraded and not reused.
Harlon Moss
Oct 27, 2023

Are introns found in prokaryotes?

Introns are rare in prokaryotes and more common in eukaryotes.
Janet White
Oct 27, 2023

Do exons evolve faster or slower than introns?

Exons usually evolve slower due to their functional constraints, while introns can accumulate changes more rapidly.
Sara Rehman
Oct 27, 2023

Do mutations in introns affect proteins?

While introns don't code for proteins, mutations in them can affect RNA splicing and gene regulation.
Aimie Carlson
Oct 27, 2023

What happens to exons during mRNA processing?

Exons are joined together to form mature mRNA after introns are removed.
Harlon Moss
Oct 27, 2023

Do exons have a role in determining protein structure?

Yes, the sequence of exons directly determines the primary structure of proteins.
Sumera Saeed
Oct 27, 2023

What is alternative splicing?

Alternative splicing is the process where introns are removed differently, resulting in multiple mRNA variants from a single gene.
Sumera Saeed
Oct 27, 2023

Do exons always code for proteins?

Exons generally code for proteins, but some may have non-coding functions.
Sumera Saeed
Oct 27, 2023

Can exons be repetitive?

Yes, some exons can contain repetitive sequences.
Harlon Moss
Oct 27, 2023

Do introns have a specific length?

Introns vary widely in length, from a few base pairs to several thousand.
Sumera Saeed
Oct 27, 2023

Are exons always contiguous in DNA?

No, exons are often separated by introns in the DNA sequence.
Harlon Moss
Oct 27, 2023

Can introns affect gene expression?

Yes, introns can contain regulatory elements that influence gene expression.
Sara Rehman
Oct 27, 2023

How do introns contribute to genetic diversity?

Introns allow for alternative splicing, creating different protein variants from the same gene.
Sumera Saeed
Oct 27, 2023

Are all introns removed from mRNA?

Typically, yes, but some transcripts might retain introns in certain cases.
Sumera Saeed
Oct 27, 2023

What happens if an exon is missing?

Missing an exon can result in incomplete or nonfunctional proteins, potentially leading to diseases.
Sumera Saeed
Oct 27, 2023

Can introns be functional?

Yes, besides being spliced out, introns can have roles in gene regulation and mRNA stability.
Janet White
Oct 27, 2023
About Author
Written by
Sumera Saeed
Sumera is an experienced content writer and editor with a niche in comparative analysis. At Diffeence Wiki, she crafts clear and unbiased comparisons to guide readers in making informed decisions. With a dedication to thorough research and quality, Sumera's work stands out in the digital realm. Off the clock, she enjoys reading and exploring diverse cultures.
Edited by
Huma Saeed
Huma is a renowned researcher acclaimed for her innovative work in Difference Wiki. Her dedication has led to key breakthroughs, establishing her prominence in academia. Her contributions continually inspire and guide her field.

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