Practice question

In fully digested linear DNA, each internal restriction cut increases fragment number by one. Starting with an intact molecule counted as one, the relationship is fragments = cuts + 1. To obtain four distinct pieces, three separate breaks must be introduced within the molecule at different recognition sequences. Two cuts would yield only three fragments, four cuts would produce five. This simple arithmetic underpins physical mapping and allows prediction of gel band number from restriction site count, essential for verifying plasmid constructs and insert release during cloning experiments.