uncorrected, results in the substitution of one base for another when the DNA is replicated. Deamination of cytosine produces uracil. Uracil differs from cytosine in its base-pairing properties and preferentially base-pairs with adenine. The DNA replication machinery therefore inserts an adenine when it encounters a uracil on the
template strand. (B) Depurination, if uncorrected, can lead to the loss of a nucleotide pair. When the replication machinery
encounters a missing purine on the template strand, it can skip to the next complete nucleotide, thus producing a nucleotide
deletion in the newly synthesised strand.