Multiple choice Alkaline phosphatase has a role in removing of unwanted nucleotides from the end of DNA adding of more nucleotides to DNA the removal of phosphate group adding of methyl group to one end of DNA Reveal answer Fill a bubble to check yourself C Correct answer Explanation Correct. As the process of ligation requires the presence of 5' phosphate group, Alkaline phosphatase is used to remove phosphate and prevent unwanted self ligation.