LABORATORY REVIEW
MOLECULAR BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a nucleotide and its partner are replaced with an “incorrect” pair of nucleotides which destroys the function of the final product.
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a nucleotide pair is added into a gene destroying the reading frame of the gene
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a frameshift mutation occurs, causing a nonfunctional protein
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a nucleotide pair substitution occurs, which causes a codon to code for an amino acid that may not be the “correct” one, although translation continues
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Detailed explanation-1: -A missense mutation is when the substitution results in a codon for a different amino acid. Because a protein’s structure is determined by the sequence of its amino acids, this can result in the protein folding into a shape different than it was intended to and therefore may have effects on its function.
Detailed explanation-2: -Missense Mutation Example A common and well-known example of a missense mutation is sickle-cell anemia, a blood disease. People with sickle-cell anemia have a missense mutation at a single point in the DNA.
Detailed explanation-3: -Missense mutations can render the resulting protein nonfunctional, and such mutations are responsible for human diseases such as Epidermolysis bullosa, sickle-cell disease, SOD1 mediated ALS, and a substantial number of cancers.
Detailed explanation-4: -A missense mutation is a DNA change that results in different amino acids being encoded at a particular position in the resulting protein.
Detailed explanation-5: -Nonsense Mutation A nonsense mutation occurs in DNA when a sequence change gives rise to a stop codon rather than a codon specifying an amino acid. The presence of the new stop codon results in the production of a shortened protein that is likely non-functional.