If you have a second fixture around, you can use the same test of putting a tube in a working socket and see if it lights. It is not uncommon in fluorescent fixtures to have the ballast burn out. You may detect a burnt smell or see the bulbs flickering.
Answer:
Gap 2 (G2): During the gap between DNA synthesis and mitosis, the cell will continue to grow and produce new proteins. At the end of this gap is another control checkpoint (G2 Checkpoint) to determine if the cell can now proceed to enter M (mitosis) and divide.
Explanation: