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.
The cell cycle is controlled at three checkpoints. The integrity of the DNA is assessed at the G1 checkpoint. Proper chromosome duplication is assessed at the G2 checkpoint. Attachment of each kinetochore to a spindle fiber is assessed at the M checkpoint.