What is the effect of a nonsense mutation?

What is the effect of a nonsense mutation?

• A. It results in a full-length protein
• B. It changes amino acid sequence but is functional
• C. It introduces a premature stop codon
• D. It stabilizes the gene expression

Answer: (C)

A nonsense mutation is a specific type of mutation in which a single nucleotide change in the DNA sequence results in the signaling of a premature stop codon during protein synthesis. This change effectively truncates the protein, leading to a shortened protein that may be nonfunctional or less functional than the full-length version. This can have significant implications for the organism, as it may disrupt the normal activity of the protein and potentially lead to various diseases or phenotypic effects. In contrast, a full-length protein would require the mutation to maintain the entire amino acid sequence without interruption by a stop codon, which is not the case with a nonsense mutation. Similarly, while some mutations may result in a change in the amino acid sequence that still produces a functional protein, a nonsense mutation does not fall into this category as it directly leads to an early termination of translation. Lastly, stabilizing gene expression refers to mechanisms that enhance the expression of a gene or its protein product and is unrelated to the direct effects of a nonsense mutation.

A nonsense mutation is a specific type of mutation in which a single nucleotide change in the DNA sequence results in the signaling of a premature stop codon during protein synthesis. This change effectively truncates the protein, leading to a shortened protein that may be nonfunctional or less functional than the full-length version.

This can have significant implications for the organism, as it may disrupt the normal activity of the protein and potentially lead to various diseases or phenotypic effects. In contrast, a full-length protein would require the mutation to maintain the entire amino acid sequence without interruption by a stop codon, which is not the case with a nonsense mutation. Similarly, while some mutations may result in a change in the amino acid sequence that still produces a functional protein, a nonsense mutation does not fall into this category as it directly leads to an early termination of translation. Lastly, stabilizing gene expression refers to mechanisms that enhance the expression of a gene or its protein product and is unrelated to the direct effects of a nonsense mutation.