Answer:
Correct choice should be:
"SGSG"
Explanation:
The cell cycle consists of G1, S, G2 and M phase. The former three phases include the interphase and M phase is the dividing phase of cell . G1 prepares cell for DNA synthesis. S phase is the phase where DNA replication takes place. G2 phase prepares cell for cell division or M phase.
G1 phase preceeds replication or S phase and G1 phase licences DNA replication.
During other phases of cell cycle, ORC complex masks origin of replication. ORC phosphorylation takes place at S phase, which removes this omplex and unmasks origin of repication site so that replication machinery can bind to it.
DNA helicase activation: S phase
DNA helicase deposition on DNA at the replication origins: G phase (actually G1)
ORC phosphorylation: S phase
Licensing of replication origins : G phase (actually G1)
Hence correct choice should be:
SGSG