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.
Investigation 7 S85 big iDea 3: genetiCs anD inforMation transfer Cyclins and CDKs do not allow the cell to progress through its cycle automatically. There are three checkpoints a cell must pass through: the G 1 checkpoint, G 2 checkpoint, and the M-spindle checkpoint (Figure 4).