Final answer:
Exon mutations are more likely to result in an altered protein due to their role in coding for protein sequences, affecting the structure and function of the protein. In contrast, mutations in introns can affect gene expression and regulation. Alternative splicing contributes to evolutionary diversity and may lead to new protein functions, whereas disruptive mutations often yield nonfunctional proteins.
Step-by-step explanation:
Mutations in exons are more likely to result in an altered protein compared to mutations in introns. This is because exons contain the actual coding sequences for proteins. Mutations here can lead to changes in the amino acid sequence of a protein, potentially affecting its function. Examples of such mutations include missense mutations, which change one amino acid for another, and can retain or alter the protein's function, and nonsense mutations, which introduce a premature stop codon, typically resulting in a nonfunctional protein. On the other hand, mutations in introns, which are non-coding sequences, are less likely to affect protein structure directly, but can still impact gene expression through effects on splicing and other regulatory functions.
Alternative splicing may give rise to protein variants with new functions, contributing to evolutionary diversity and adaptation. Gene duplication also contributes to this process by creating redundant copies of genes, which can then evolve independently. Certain mutations, such as those affecting splicing mechanisms or recognition sequences, can lead to alternative splicing and generation of new protein variants without compromising the function of the original protein.
However, mutations that disrupt normal splicing mechanisms can also result in the production of nonfunctional proteins and are a common cause of genetic diseases. A frameshift mutation caused by an insertion or deletion of nucleotides not in multiples of three can change the reading frame, severely altering the protein's amino acid sequence, often leading to a loss of function.