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.
This concept underscores an important feature: presence of ssDNA signals that something is wrong and this also holds true for other phases of the cell cycle. In other words, whether ssDNA is created during replication, or outside of S phase, it will always trigger the checkpoint surveillance system (Figure 3).