Final answer:
Frameshift mutations at the beginning of the genetic code are more harmful than those at the end because they change more of the message.
Step-by-step explanation:
A frameshift mutation occurs when a base pair is inserted or deleted in the DNA sequence, causing a shift in the reading frame of the genetic code. This type of mutation is more harmful when it occurs at the beginning of the code because it changes more of the message. For example, if one nucleotide is inserted, it will affect every codon that follows, potentially altering the entire protein sequence. On the other hand, if three nucleotides are inserted, the reading frame may be restored after a few codons, resulting in fewer changes to the protein. Therefore, frameshift mutations at the beginning of the code are more harmful than those at the end.