Final answer:
A mutation in the third base of a codon usually has less severe effects due to the redundancy of the genetic code, which can tolerate some variability at the 'wobble base'. However, a point mutation like a single base insertion or deletion can cause frameshift mutations, having significant consequences for protein synthesis. A mutation from cytosine to adenine can disrupt proper base pairing and affect the protein product.
Step-by-step explanation:
When a mutation occurs at the third base in a codon, also known as the wobble base, the effects might be less severe due to the redundancy of the genetic code. The first two bases of a codon are usually more critical in determining the amino acid being incorporated into a protein. A change in the third base might not even alter the amino acid specified by the codon because multiple codons can code for the same amino acid.
For example, if third base is a 'U', 'C', 'A', or 'G', it might still code for the same amino acid if the first two bases are unchanged. In contrast, a point mutation such as an insertion or deletion can significantly disrupt the reading frame, leading to what is known as a frameshift mutation. If three nucleotides are added or deleted, the reading frame is maintained, but a single nucleotide change can radically alter the entire downstream amino acid sequence.
This can have a profound effect on the protein's structure and function, and potentially, on the organism's health and development. However, if a cytosine is replaced with an adenine, this would affect how the changed strand will base pair with its complementary strand, possibly leading to improper protein synthesis.