What is the difference between a nonsense mutation and a frame shift mutation?

Answer 1

A point mutation is where a single letter is the only thing changed in the DNA sequence. Lets say your phone number (or DNA code) was 483-1839 and you mistakely told someone that your phone number was 483-1835. that one digit is enough to make that person dial the wrong number (or cause a mutation in DNA.) For example suppose your DNA sequence was ACT GCT, a point mutation would just be a change in one of those bases (or letters), so it could end up something like : ACT ACT.

EX: GTA CTG CAA-----> (point mutation) -----> GTA GTG CAA

A frameshift mutation is generally much more serious and will cause a change all the way down a DNA sequence, making each codon (or every group of three bases) a different sequence, not just in one point or base like a point mutation, that would only slightly change the sequence of a single codon. A frameshift mutation happens not when a DNA base is simply changed, but when a whole base is added or deleted from the sequence of DNA. For example lets suppose your DNA sequence is GTA CCT AGG. In a frameshift mutation a whole base would be added somewhere in that sequence, making it look something like this: GTAT CCT AGG. Since it is impossible though to have 4 bases in a codon, your body would automatically shift every letter down one, even to the next codon in the sequence, to make room for this new base. In the end the final product would look something like this: GTA TCC TAG (with the left over G being the first base in the next codon, and so on).

EX: CAG TTC CTG GAA -----> (frameshift muation) -----> CAG TTA CCT GGA

As you can see the frameshift mutation would leave the mutated DNA vastly more different from its parent DNA (that it was replicated from), then a point mutation would, though in both cases the DNA would still be different/mutated. This is because the codons would be more considerbaly changed with the frameshift (where now the sequence in every codon in different), rather than in a point mutation (where only one of the codons would be different).

Hope this helps all you HS Bio 1 people like myself out there, or anyone else studying this subject.

-- K.J.S

Answer 2

They are similar in that they both alter the base sequence of DNA. This is what is meant by the term "mutations".

They are different in that a point mutation (substitution), if it occurs in a coding region, can affect, at most, only one codon, and therefore cause an alteration of only one amino acid in the polypeptide being coded for. It may not even have that much effect, if the substitution is in the third position of the codon, because the genetic code is degenerate, and two, three, or four codons (usually beginning with the same two bases) may code for the same amino acid.

By contrast, an insertion or deletion will cause frameshift. This means that every codon downstream of the mutation is changed, and therefore all the amino acids encoded by this segment of DNA will probably be different.

All the above assumes that the mutations occur in a region coding for a polypeptide. There are also segments of DNA that code for various other gene products, such as types of RNA, as well as non-coding regions of DNA.

Answer 3

Frameshift are in the inside point is on the outside.

frameshift is deletion or addition of 1 base. Many amino acids are changed.

Point mutation: 1 base is changed, 1 amino acid is changed.

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That is so wrong! Point mutations CAN be frameshift mutations, if it is a 'deletion' or 'insertion' point mutation it acts as a frameshift mutation as all subsequent codons will be read differently.

For example if the code was AGGAGC the amino acids are 'AGG' and 'AGC'. If a C was inserted so it read 'AGCGAGC' the amino acids coded for are 'AGC' 'GAG' and all after are changed.

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Mutation is any change in the sequence of the nucleotides in the DNA.

A point mutation is a simple change in one base of the nucleotide sequence.

A frame shift mutation is when one or more bases are inserted or deleted. But because our cells read DNA in three letter "words," adding or removing one letter changes the meaning of the word. This type of mutation can make the resulting protein different and probably non-functional.

Answer 4

The substitution of one nucleotide for another will probably [see wobble bases] result in a triplet-codon-reading-frame error for only that one triplet codon involved, whereas either a deletion or the addition of a nucleotide from or to the DNA sequence of bases will alter the triplet-codon-reading-frame for ALL CODONS that follow from the affected site. The reason for this is that the addition or deletion of, say, a single nucleotide SHIFTS the Reading Frame into unintelligible code.

Answer 5

Point mutations are when one nitrogenous base in the DNA strand is changed to something else. Frameshift mutations are when a base is added or deleted, causing the rest of the bases after it to shift down one or move up one. Frameshift mutations can be much more dangerous because it changes many more base pairs than a point mutation.

Answer 6

They are similar because they both alter the base sequence of DNA.

Answer 7

Different- substitution mutations only affect one codon, frameshift mutations affect all triplets downstream