HEREDITY
MUTATIONS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Change one amino acid to a stop codon.
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Change one amino acid to a different amino acid.
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Change one amino acid to a start codon.
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Detailed explanation-1: -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.
Detailed explanation-2: -A nonsense mutation changes the codon for an amino acid into the codon for a “STOP” signal. This completely changes the structure of the protein, because anything after the “STOP” signal is ignored. The ribosome snips off the incomplete protein, and goes on its way.
Detailed explanation-3: -(NON-sens myoo-TAY-shun) A genetic alteration that causes the premature termination of a protein. The altered protein may be partially or completely inactivated, resulting in a change or loss of protein function.
Detailed explanation-4: -Point mutations in a DNA sequence that cause the replacement of the normal codon for an amino acid by one of the three termination (or “stop”) codons are callednonsense mutations.
Detailed explanation-5: -In genetics, a nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in leading to a truncated, incomplete, and nonfunctional protein product.