The UK's most valuable monument is deemed to be the 1,000-year-old Tower of London, which is worth an estimated Â£56billion to the British economy and came it at number five in the list of European list. Its value is six times more than its nearest rival the Colosseum in Rome, which is valued at Â£72billion.
Cell cycle checkpoints are control mechanisms in eukaryotic cells which ensure proper division of the cell.
Interphase. The interphase portion of the cell cycle is relatively long compared to mitosis. Interphase consists of three stages: first gap (G1), synthesis (S) and second gap (G2). The cell replicates DNA only in the S phase. Before the cell can transition from G1 to S, it must clear the G1 checkpoint.