Answer;
DNA replication is semi-conservative.
The meselson-stahl experiment supported the hypothesis that DNA replication is semi-conservative.
Explanation;
The Meselson-Stahl experiment was an experiment by Meselson and Stahl that proved that the semi-conservative model by Watson and Crick was correct.
DNA replication is semi-conservative in the sense that the new helices formed after replication contain, one new DNA strand and one old strand from the parent DNA molecule.
Answer:
DNA Ligase
Explanation:
DNA ligase is an enzyme that connects nucleotides of DNA from the phosphate to the sugar. This seems to match the provided description, therefore I believe it to be the correct answer.