Asked by: Shaira Tietzsch
science genetics

What is an exon in biology?

Last Updated: 20th January, 2020

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An exon is any part of a gene that will encode a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term exon refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts.

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Also, what is an exon and intron?

Introns and exons are nucleotide sequences within a gene. Introns are removed by RNA splicing as RNA matures, meaning that they are not expressed in the final messenger RNA (mRNA) product, while exons go on to be covalently bonded to one another in order to create mature mRNA.

Secondly, what is an intron in biology? Definition. noun, plural: introns. (molecular biology) A noncoding, intervening sequence of DNA within a gene that is transcribed into mRNA but is removed from the primary gene transcript and rapidly degraded during maturation of the RNA product. Supplement. An intron is a nucleotide sequence within a gene.

Hereof, what is the function of Exon?

An exon is a coding region of a gene that contains the information required to encode a protein. In eukaryotes, genes are made up of coding exons interspersed with non-coding introns. These introns are then removed to make a functioning messenger RNA (mRNA) that can be translated into a protein.

Is an exon a codon?

Short answer: An exon is a part of a transcribed gene (from DNA) before the RNA has been subject to post-transcriptional modification (cf. intron). A codon is any three consecutive RNA nucleobases within a reading frame.

Related Question Answers

Ludwig Raymond

Professional

What is the purpose of an intron?

While introns do not encode protein products, they are integral to gene expression regulation. Some introns themselves encode functional RNAs through further processing after splicing to generate noncoding RNA molecules. Alternative splicing is widely used to generate multiple proteins from a single gene.

Aydan Caracena

Professional

How many codons are there?

Any single set of three nucleotides is called a codon , and the set of all possible three-nucleotide combinations is called "the genetic code" or "triplet code." There are sixty-four different combinations or codons (4 × 4 × 4 = 64).

Isam Pochechikin

Professional

Where does splicing occur?

For nuclear-encoded genes, splicing takes place within the nucleus either during or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein.

Abelina Reboul

Explainer

What is an Extron?

In short, the extron (sometimes seen as “exon”) is the part of a gene that is expressed. This turns out to be only about 3% of the human genome. The other 97% are introns which are interspersed throughout our DNA between the extrons and are not expressed at all.

Ibrain Ukhovsky

Explainer

What is mRNA made of?

Messenger RNA (mRNA) Messenger RNA (mRNA) is a single-stranded RNA molecule that is complementary to one of the DNA strands of a gene. The mRNA is an RNA version of the gene that leaves the cell nucleus and moves to the cytoplasm where proteins are made.

Jun Lopez De Arbina

Explainer

Are introns transcribed?

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.

Codi Pousa

Pundit

How do Anticodons function?

Anticodons are found on molecules of tRNA. Their function is to base pair with the codon on a strand of mRNA during translation. The anticodon sequence will bind to the codon of the mRNA, allowing the tRNA to release the attached amino acid. This amino acid is then added to the peptide chain by the ribosome.

Frieda Happold

Pundit

Why are introns removed?

Not only do the introns not carry information to build a protein, they actually have to be removed in order for the mRNA to encode a protein with the right sequence. If the spliceosome fails to remove an intron, an mRNA with extra "junk" in it will be made, and a wrong protein will get produced during translation.

Gisel Churshukov

Pundit

What are ribosomes made of?

A ribosome is made from complexes of RNAs and proteins and is therefore a ribonucleoprotein. Each ribosome is divided into two subunits: a smaller subunit which binds to a larger subunit and the mRNA pattern, and. a larger subunit which binds to the tRNA, the amino acids, and the smaller subunit.

Eriko Sambruno

Pundit

Who discovered junk DNA?

The term “junk DNA” was first used in the 1960s, but was formalized by Susumu Ohno in 1972. Ohno noticed that the amount of mutation occurring as a result of deleterious mutations set a limit for the amount of functional loci that could be expected when a normal mutation rate was considered.

Asel Daverkausen

Pundit

Are all exons coding?

The exons are the sequences that will remain in the mature mRNA. Thus, the exons contain both protein-coding (translated) and non-coding (untranslated) sequences. Also note that the transcription of all mRNAs begins and ends with an exon and introns are located between exons.

Bose Undio

Teacher

What do genes code for?

The genome of an organism is inscribed in DNA, or in some viruses RNA. The portion of the genome that codes for a protein or an RNA is referred to as a gene. Those genes that code for proteins are composed of tri-nucleotide units called codons, each coding for a single amino acid.

Policarpo Grunseisen

Teacher

What is cistron in biology?

A cistron is an alternative term for "gene". The word cistron is used to emphasize that genes exhibit a specific behavior in a cis-trans test; distinct positions (or loci) within a genome are cistronic.

Elizaveta Galbarriarto

Teacher

Are introns coding or noncoding?

Introns are non-coding sections of a gene, transcribed into the precursor mRNA sequence, but ultimately removed by RNA splicing during the processing to mature messenger RNA. Many introns appear to be mobile genetic elements.

Zoita Croger

Teacher

Why do exons exist?

In other words, they are in our genes because they have been used during evolution as a faster pathway to assemble new genes. Over the past 10 years, the exon shuffling idea has been supported by data from various experimental approaches.

Yeimi Godrid

Reviewer

What happens during transcription?

Transcription takes place in the nucleus. It uses DNA as a template to make an RNA molecule. RNA then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation occurs. Translation reads the genetic code in mRNA and makes a protein.

Hailey Pflumm

Reviewer

What happens during translation?

Translation is the process by which a protein is synthesized from the information contained in a molecule of messenger RNA (mRNA). Translation occurs in a structure called the ribosome, which is a factory for the synthesis of proteins.

Xuehong Foya

Reviewer

What is the benefit of introns?

Introns are crucial because the protein repertoire or variety is greatly enhanced by alternative splicing in which introns take partly important roles. Alternative splicing is a controlled molecular mechanism producing multiple variant proteins from a single gene in a eukaryotic cell.

Cheila Papageorge

Reviewer

What do introns contain?

intron / introns. In some genes, not all of the DNA sequence is used to make protein. Introns are noncoding sections of an RNA transcript, or the DNA encoding it, that are spliced out before the RNA molecule is translated into a protein. The sections of DNA (or RNA) that code for proteins are called exons.