Which of the following mutations would be most likely to have a harmful effect on an organism? (1 point)
A. • all mutations have a harmful effect on organisms
B. • a substitution of a thymine for an adenine
C. • a deletion of 3 bases near the center of a gene
D. • there is not enough information to know whether a mutation would be harmful
C. • a deletion of 3 bases near the center of a gene
To determine which of the following mutations would be most likely to have a harmful effect on an organism, let's analyze each option:
A. "All mutations have a harmful effect on organisms." This statement is incorrect as not all mutations are harmful. In fact, some mutations can be neutral or even beneficial.
B. "A substitution of a thymine for an adenine." This type of mutation, known as a point mutation or a nucleotide substitution, can indeed have harmful effects on an organism. It can lead to a change in the codon sequence, resulting in a different amino acid being incorporated into the protein during translation. This alteration can potentially disrupt the protein's structure and function.
C. "A deletion of 3 bases near the center of a gene." This type of mutation, specifically a frameshift mutation, can have a significant impact on the resulting protein. During translation, the deletion shifts the reading frame, causing a change in all subsequent codons. This often leads to a non-functional or severely altered protein, making this mutation likely to be harmful.
D. "There is not enough information to know whether a mutation would be harmful." Without any specific information about the mutation, it is accurate to say that we cannot determine if it would be harmful or not.
Considering the above analysis, the mutation most likely to have a harmful effect on an organism is option C, the deletion of 3 bases near the center of a gene.
The correct answer is C. a deletion of 3 bases near the center of a gene.
While it is not accurate to say that all mutations have a harmful effect on organisms (choice A), some mutations can indeed be harmful. However, the specific nature of the mutation will determine its effect.
In choice B, a substitution of a thymine for an adenine is a point mutation, which can result in a change in the amino acid sequence of a protein. Depending on the location and function of the affected protein, this change may or may not be harmful.
In choice C, a deletion of 3 bases near the center of a gene can cause a frameshift mutation. This means that the reading frame of the gene is altered and can lead to a completely different amino acid sequence. This type of mutation is more likely to have a harmful effect because it can significantly affect the structure and function of the protein produced by the gene.
Therefore, based on the information available, the most likely mutation to have a harmful effect on an organism is a deletion of 3 bases near the center of a gene (choice C).