Which of the following mutations would likely be most dangerous to a cell?

Question

Substitution of one nucleotide for another
Deletion of three nucleotides
Deletion of one nucleotide

Answer 1

To assess which of the mutations might be the most dangerous to a cell, we can analyze the impact of each type of mutation:

1. Substitution of one nucleotide for another: This type of mutation can lead to a silent mutation (no change in the amino acid), a missense mutation (change in one amino acid), or a nonsense mutation (creation of a stop codon). The impact varies, but it is generally less catastrophic than a frameshift mutation.

2. Deletion of three nucleotides: This deletion removes a complete codon, which means that one amino acid would be missing from the protein. While this could affect protein function, it does not change the reading frame of the mRNA.

3. Deletion of one nucleotide: This causes a frameshift mutation, altering the reading frame of the mRNA downstream of the deletion. This type of mutation typically has more severe consequences because it can lead to the production of a completely different and usually nonfunctional protein, as well as premature stop codons.

Given these analyses, the deletion of one nucleotide would likely be the most dangerous to a cell, as it can result in extensive changes to the protein's structure and function due to the frameshift effect.