Final answer:
When 5-bromouracil (5BU) is in its rare form, it can pair with guanine instead of its usual pair, adenine. This can cause genetic mutations during DNA replication by leading to a guanine-cytosine pair, which replaces the original adenine-thymine pair.
Step-by-step explanation:
The student is asking about the pairing of 5-bromouracil (5BU) when it adopts its rare form. 5-bromouracil is a chemical compound that can be incorporated into DNA in place of thymine. Normally, thymine pairs with adenine during DNA replication. However, when 5-bromouracil is in its rare enol or ionized form, it can pair with guanine instead of adenine. This pairing leads to a change in the original DNA sequence in subsequent DNA replications, as guanine will pair with cytosine, which replaces the original adenine-thymine pairing with a guanine-cytosine pairing.
Understanding the effects of 5-bromouracil and its rare form pairing is important in the study of mutagenesis and has implications in the field of genetic research and medicine. The ability of 5BU to induce mutations by mispairing during DNA replication is an example of how external compounds can affect genetic information, making it a subject of interest in genetic research.