The change from CGACCTGAA to CGACCTCAA involves a single nucleotide substitution: the 'G' in the original sequence is replaced by a 'C'. This type of mutation is called a point mutation or base pair substitution.
To determine what effect this has on the protein, we can look at the codon sequences that correspond to the DNA sequences. The original sequence CGACCTGAA could be translated into a specific amino acid (depending on the reading frame and the genetic code), whereas CGACCTCAA would translate into a potentially different amino acid.
Based on the options provided:
- Option a suggests a point mutation substitution resulting in a different protein. This could be correct if the amino acid encoded changes, so this is a plausible answer.
- Option b references an amino acid deletion, which does not apply here since it’s not a frameshift mutation.
- Option c states a base pair substitution resulting in the same protein, which may also be correct if the substitution does not change the amino acid (this is less likely but possible).
- Option d states a frameshift mutation, which is also incorrect because the given mutation does not shift the reading frame.
Since the change results in one base pair substitution, the best choice is option a: a point mutation substitution resulting in a different protein. However, it should be noted that whether a different protein is produced or not depends on the specific context of the codons involved and their corresponding amino acids.