Final answer:
A base analog is a chemical mutagen that is structurally similar to a nucleotide but has different base-pairing rules. It can be incorporated into DNA during replication, leading to mutations.
Step-by-step explanation:
A base analog is a chemical mutagen that is structurally similar to a nucleotide but has different base-pairing rules. It can be incorporated into DNA during replication, leading to mutations. One example of a base analog is 5-bromouracil, which is a nucleoside analog to thymine. It pairs with guanine instead of adenine, resulting in a conversion of an AT base pair to a GC base pair.
Base analogs introduce mutations by altering the base-pairing properties of DNA. When a base analog is incorporated into the replicating DNA, it pairs with a different base than the original nucleotide would, leading to a change in the DNA sequence.
In contrast, other types of chemical mutagens, such as UV light and intercalating agents, introduce mutations by causing structural changes or distortions in the DNA molecule, which can result in insertions, deletions, or frameshift mutations.