Which of the Following Can Be Said About a Frameshift Mutation?
The DNA sequence of a gene tin can exist altered in a number of ways. Cistron variants (likewise known every bit mutations) can take varying furnishings on wellness, depending on where they occur and whether they alter the function of essential proteins. Variant types include the following:
Substitution
This type of variant replaces one Dna edifice block (nucleotide) with another. Substitution variants can be further classified by the effect they take on the production of protein from the altered factor.
- Missense:A missense variant
is a type of substitution in which the nucleotide change results in the replacement of one poly peptide edifice block (amino acid) with another in the protein made from the gene. The amino acid change may alter the office of the protein.
- Nonsense: A nonsense variant is another type of substitution. Instead of causing a modify in ane amino acid, notwithstanding, the altered Deoxyribonucleic acid sequence results in a stop signal that prematurely signals the jail cell to stop building a protein. This type of variant results in a shortened protein that may office improperly, be nonfunctional, or get broken downwards.
Insertion
An insertion changes the Deoxyribonucleic acid sequence by adding one or more than nucleotides to the gene. Every bit a result, the protein fabricated from the gene may not function properly.
Deletion
A deletion changes the Dna sequence by removing at least i nucleotide in a cistron. Small deletions remove one or a few nucleotides within a gene, while larger deletions can remove an entire gene or several neighboring genes. The deleted Deoxyribonucleic acid may modify the part of the affected poly peptide or proteins.
Deletion-Insertion
This variant occurs when a deletion and insertion happen at the same fourth dimension in the same location in the cistron. In a deletion-insertion variant, at least ane nucleotide is removed and at least one nucleotide is inserted. Nonetheless, the modify must be complex enough to differ from a simple substitution. The resulting protein may not function properly. A deletion-insertion (delins) variant may as well be known as an insertion-deletion (indel) variant.
Duplication
A duplication occurs when a stretch of one or more than nucleotides in a gene is copied and repeated next to the original Deoxyribonucleic acid sequence. This blazon of variant may modify the function of the poly peptide made from the gene.
Inversion
An inversion changes more than one nucleotide in a gene by replacing the original sequence with the same sequence in reverse gild.
Frameshift
A reading frame consists of groups of three nucleotides that each code for one amino acid. A frameshift variant occurs when there is an addition or loss of nucleotides that shifts the grouping and changes the lawmaking for all downstream amino acids. The resulting poly peptide is usually nonfunctional. Insertions, deletions, and duplications tin can all be frameshift variants.
Echo expansion
Some regions of Deoxyribonucleic acid contain brusk sequences of nucleotides that are repeated a number of times in a row. For example, a trinucleotide repeat is made upward of sequences of iii nucleotides, and a tetranucleotide repeat is fabricated up of sequences of four nucleotides. A repeat expansion is a variant that increases the number of times that the short DNA sequence is repeated. This blazon of variant tin cause the resulting protein to function improperly.
Source: https://medlineplus.gov/genetics/understanding/mutationsanddisorders/possiblemutations/
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