Two important checkpoints that regulate the cell's progression through the cell cycle occur in the and phases of the cell cycle. see section 12.3 (page 264) .

Two important checkpoints that regulate the cell's progression through the cell cycle occur in the G1 and G2 phases of the cell cycle.

G1 (restriction) checkpoint  - the cell becomes committed to entering the cell cycle

G2 checkpoint - chromosomes have replicated successfully.

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micro/nanoscale topography surface exhibits many prominent properties and is extensively employed in biomedical device, microfluidic device and energy device fabrication. additionally, the clinical applications of biomaterials can be largely expanded with of nanostructured surfaces.