Final answer:
A single base pair substitution in the middle of an exon could result in a silent, missense, or nonsense mutation affecting the transcript of a eukaryotic gene. The transcript will have an altered nucleotide sequence, and the resultant protein might have changes in structure and function or be nonfunctional if a stop codon is introduced.
Step-by-step explanation:
If a eukaryotic gene underwent a single base pair substitution in the middle of an exon, the effect on the transcript of that gene could vary depending on the nature of the substitution. A point mutation, which is a type of substitution mutation, could lead to one of three outcomes:
- A silent mutation where the altered codon still codes for the same amino acid, due to the redundancy of the genetic code.
- A missense mutation where the altered codon codes for a different amino acid, which may alter the protein's structure and function.
- A nonsense mutation where the altered codon becomes a stop codon, leading to premature termination of translation and potentially a truncated, nonfunctional protein.
The effect on the gene's transcript specifically would be the presence of an altered nucleotide sequence. The impact on the protein, however, would depend on the specific mutation and where in the protein the amino acid change occurred.