DNA Replication Practice Test

After replication, each daughter DNA molecule contains one parental strand and one newly synthesized complementary strand. A researcher observes a point mutation present in only one of the two sister chromatids immediately after S phase. Which explanation best accounts for this observation?

Replication requires unwinding of the double helix and stabilization of exposed single-stranded templates so they do not reanneal. A mutation prevents single-strand binding proteins from attaching to separated DNA, but polymerase function is normal. Which outcome is most likely at the replication fork?