A missense mutation is a point mutation.
A point mutation is an alteration that only changes a single nucleotide of nucleic acid. It mainly involves the exchange of one base to another. It also includes deletions or insertions of a single nucleotide. As far as, the point mutation is a common type of mutation. Single base replacement can be differentiated into two types:Transitions: It exchanges nucleotide from pyrimidine to pyrimidine and purine to purine. Transversions: It exchanges nucleotide from purine to pyrimidine.
When a point mutation affects the coding region, it can be allocated to one of the following group, according to the result of the mutation:Silent mutation: Mainly, it does not alter the related amino acid, and thus has no assessable effect on the genome. Missense mutation: it changes the related amino acid, and thus have an effect on the genome. If the properties of the amino acid (a charge, polarity, etc.) stay the same, then the transformation is called conservative, in which case it may not affect the protein's function. Also, the resultant mutation is called non-conservative, and it affects the protein function and end result in disease. Nonsense mutation: It replaces the stop codon for a natural codon, which causes the protein's truncation. This also affect the protein functioning.
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Grade: High School
Chapter: DNA repair and mutation
Missense mutation, nonsense mutation, non- conservative, transition, transversion, purine, pyramidine, mutation, disease.
a point mutation only mutates and changes that particular spot in the DNA strand while a frameshift changes the whole strand by moving the bases either one forward or backward
The correct answer is- A) silent mutation.
Mutation can be described as a permanent change in the nucleotide sequence of DNA (deoxyribonucleic acid), which is considered as the genetic material of life forms.
Silent mutation is a type of point mutation in which change in one nucleotide sequence of DNA does not cause any change in the amino acid sequence of the protein that is produced by the DNA.
This is because of the fact that more than one codon (sequence of three nucleotide coding for an amino acid) can code for a particular amino acid.
In this question, CUC is changed to CUG after point mutation. Both of these codons code for the same amino acid that is leucine.
Therefore, it will not bring any change in the amino acid sequence of protein.
Thus, a silent mutation has occurred.
4. c. Deletion/ frameshift mutation
5. a. Tyr Tyr Asp Ser Gly
6. A frameshift occurred which altered the identity of the amino acids following the initiator 6. methionine, but not the length of protein Q.
A single base pair at the first position of the Arg codon i.e. CGA has been deleted. Due to the deletion, the reading frame has shifted one nucleotide backwards, altering the amino acid sequence of the protein.
The genomic DNA sequence is 5'-ATG ATA CTA AGG CCC-3'. Therefore, the complementary mRNA will be 5'-UAC UAU GAU UCC GGG-3'. According to the genetic code, this mRNA sequence encodes the following amino acid sequence: Tyr Tyr Asp Ser Gly
The wild type DNA sequence is:
The mutant i.e. mRNA with the added G will be
This is a single base pair insertion and frameshift mutation that shifts the reading frame one base pair forwards. The codon that was originally GAG coding for glutamic acid (Glu) gets converted to GGA that codes for glycine. Therefore, the amino acid sequence has been altered but the polypeptide chain will still have 13 amino acids.
5'-ACTCGTGA-3'-frameshift mutation (number of nucleotides in a DNA sequence is not divisible by three). deletion, one nucleotide in DNA is deleted, in this case A
5'-ATTACGTGA-3'- base substitution, C is substituted with T
5'-ACTACGTGT-3'- base substitution, A is substituted with T
5'-ACTAAGTGA-3'- base substitution, C is substituted with A
Substitution is a type of mutation in whichonly one base is changed. They can be:
•Nonsense mutations-when substitution leads to the formation of a stop codon instead of a codon
•Missense mutations-when one nucleotide is substituted and a different codon is formed
• Silent mutations-when a nucleotide is substituted and the same amino acid is produced
a frameshift mutation would likely have a larger effect because it changes many codons.
(*a point mutation might also have a large effect, for example, if it changes a codon for an amino acid into a stop codon)
a. GC->CG in the protein coding region on a gene. - Base substitution
b. GC->TA in a GAA glutamate codon - Base substitution
c. Loss of three bases GAA for a glutamate codon - Deletion
d. GC->CG in a tRNA gene - Insertion
e. GC->AT in the ribsome binding site of a mRNA - Frameshift mutation
DNA mutation occurs as a result of a change in the gene sequence of the protein being coded by the genes. Several causes of mutation involve radiation, heavy metal exposure, etc. There are different types of gene mutation. These include a deletion where the bases are deleted. Another one is the insertion where a base is inserted into the sequence. This lengthens the base sequence of the gene. Another mutation is the base mutation -this can take place as a result of inversion. Inversion reverses the order of the bases in a sequence like this: normal CGGA → AGGC
These mutations result in disorder e'g Downs syndrome, Puckingtons disease, Cystic fibrosis etc.
Addition type of mutation occurred for mutated sequence and Frameshift was the result
Deletion, insertion happens in frameshift mutation. In this process bases are that are either subtracted or added and not divisible by three. When nucleotides replaced another frameshift, mutation don’t include the substitution.
It Is the most deleterious change to the coding sequence of protein. It has capability for leading a premature end to the translation of mRNA and also formation of extended polypeptide. It is also called framing error
Correct answer is D.
Silent mutations have no observable effect while neutral mutations does not cause harm or benefit the organism in any way. Missense mutations are single nucleotide changes that only affect one codon and one protein. In this case answer is frameshift mutation because this type of mutation is result of DNA insertion or deletion which changes the way DNA sequence is read and may affect more than one gene.