Across 1. signalling protiens recieved at the plasma membrane 3. includes mitosis and cytokinesis 5. each double helix 7. body cells 9. when DNA and replication occurs 10. programmed cell death 14. division of the cytoplasm 16. "bring about apoptosis"

Down 2. the 2 identical chromatid 4. a family of internal signalling proteins that increase and decrease as the cell cycle continues, specific ones must be present for the cell to proceed from the G1 stage all the way to the M stage 6. when a cell preforms its usual functions, preparation for mitosis are being made, the cell spends most of the cell cycle in this phase 8. orderly set of stages the take place between the time a eukaryotic cell divides and the time the resulting daughter cells also divide 11. a signalling protien in mammilian cells that stops the G1 cycle when DNA is damaged, it can attempt to initiate repair of the DNA, but rising levels of this protien can cause apoptosis 12. retinoblastoma, protein that is responsible for interpreting growth signals 13. nuclear division 15. stage before DNA replication by recovering from previous division, grows in size, and accumulating materials that will be used for DNA synthesis 17. an agent that influences the activities of a cell, ensure that the cell cycle stages follow one another in the normal sequence 18. the stage where cells synthesize proteins that will assist cell division, the stage from the completetion of DNA replication to the onset of mitosis