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.
Checkpoints of cell-cycle control system ensure that: A. the environment is favorable for the cell to initiate DNA replication. B. M phase is completed before cytokinesis begins. C. all chromosomes are attached to the mitotic spindle before the chromosomes are segregated to the two daughter cells.