Final answer:
A mutation that replaces cytosine with adenine in DNA will disrupt the base pairing and can have consequences on the structure and function of the DNA.
Step-by-step explanation:
When a mutation occurs and cytosine is replaced with adenine in DNA, it will affect the structure of DNA. Cytosine forms base pairs with guanine, and adenine usually pairs with thymine. By replacing cytosine with adenine, the base pairing will be disrupted, leading to a mismatch in the DNA strand. This can result in changes in the genetic code and potentially affect the function of the DNA.