Final answer:
The addition or loss of 6 nucleotides, given the code is a triplet, reestablishes the subsequent reading frame without causing a frameshift mutation, potentially adding or deleting two amino acids.
Step-by-step explanation:
The addition or loss of 6 nucleotides could have different effects depending on whether these nucleotides are added or lost as multiples of three. Since the code is a triplet, adding or losing nucleotides in multiples of three, such as 6, does not result in a frameshift mutation. Instead, it would result in either the addition or the removal of two amino acids, effectively reestablishing the reading frame after the insertion or deletion. Therefore, the correct answer is the reestablishing of the subsequent reading frame.
Frameshift mutations occur when the number of nucleotides added or lost is not a multiple of three, causing all subsequent codons to be read incorrectly, and usually leading to nonfunctional proteins. Since 6 is a multiple of three, nucleotides added or lost in such a group would avoid a frameshift mutation. However, the effect on the protein's functionality would depend on the role and position of the two amino acids that are added or removed.