Final answer:
The loss of 5' to 3' exonuclease activity in DNA polymerase 1 would impair the removal of RNA primer nucleotides, resulting in incomplete DNA replication.
Step-by-step explanation:
DNA polymerase 1 is an enzyme involved in DNA replication and repair. It is responsible for removing RNA primer nucleotides and replacing them with the appropriate deoxynucleotides to form DNA. The 5' to 3' exonuclease activity of DNA polymerase 1 is crucial for this process. If this activity is destroyed due to a mutation, it would result in the inability of the enzyme to remove the RNA primer, leading to incomplete replication of DNA strands.