Final answer:
In the context of a genetic code where codons are sequences of six nucleotides, the addition or loss of three nucleotides would not restore the reading frame; it would disrupt the sequence of sextuplets and thus likely result in an altered protein sequence beyond the mutation point.
Step-by-step explanation:
The question revolves around the concept of the genetic code and how it is read during the process of protein translation. The genetic code is comprised of codons, which are typically sequences of three nucleotides that specify individual amino acids.
When a frameshift mutation occurs, such as the insertion or deletion of nucleotides, it can drastically alter the resulting protein. If one or two nucleotides are added or removed, the entire reading frame shifts, leading to a completely different sequence of amino acids from that point onward. This can severely affect protein function.
However, according to experiments by scientists like Francis Crick and Sydney Brenner, the insertion of three nucleotides adds one extra amino acid but does not alter the reading of subsequent codons. This means the integrity of the protein, beyond the point of mutation, remains intact. Similarly, in the hypothetical scenario of a sextuplet code where codons are six nucleotides long, the addition or loss of three nucleotides would not restore the reading frame, as it would still disrupt the sequence of sextuplets.