Spontaneous mutation occurs when
A) a DNA base is in a rare tautomeric form as the replication fork arrives, and a mismatched base is inserted.
B) a person smokes cigarettes or is exposed to a teratogen for many years.
C) the sugars and phosphates in the DNA double helix exchange places.
D) thymine temporarily becomes uracil.
E) a replication fork stalls.

Question

Quizplus · Accepted Answer

Spontaneous mutation occurs when a DNA base is in a rare tautomeric form as the replication fork arrives, and a mismatched base is inserted. Tautomeric shift is a temporary change in the structure of a nucleotide base that creates a nonstandard Watson-Crick base pairing. This can result in the insertion of a wrong nucleotide during DNA replication, leading to a mutation.

Spontaneous Mutation Occurs When