21. Proteins which help to open the double helix for DNA synthesis are
A. DNA helicases
B. single stranded binding proteins
C. ligase
D. DNA topoisomerase
22. First evident that DNA is genetic material comes from the experiment of Griffith is
A. transduction
B. transformation
C. replication
D. translation
23. An RNA primer is synthesized by
A. DNA helicases
B. ligase
C. DNA topoisomerase
D. primase