Homework from last class: Complete storyboard for mitosis project Bring materials and camera 1

Note: A blue box surround the notes you should copy 2

Cytokinesis, Checkpoints in the Cell Cycle, and Cancer Chapter 5.1 pp. 158-161 3

Cytokinesis cytokinesis: the final stage of the cell cycle; separates the 2 nuclei and cell contents into 2 daughter cells. New cells are identical to the parent cell. Parent cell (in telophase) 2 identical daughter cells 4

Animal cells – cell membrane pinches together to divide the cell’s cytoplasm and organelles Plant cells – a cell plate forms along the centre of the cell to divide the cell into 2 daughter cells 5

Checkpoints in the Cell Cycle Activities in the cell cycle are monitored and controlled at specific stages (checkpoints). Proteins at these checkpoints monitor cell activities send info to nucleus instructs the cell whether or not to divide Cells will not divide if: Not enough nutrients to support cell growth DNA in nucleus has not been replicated DNA is damaged 6

Checkpoints in the Cell Cycle 7

Cancer If a mutation occurs in a gene producing the instructions for a checkpoint protein, cell cycle control will be lost  can lead to uncontrolled division (cancer) 8

Healthy cells stop dividing when they receive messages from neighbouring cells; cancer cells do not respond to messages from nearby cells  continue to divide  tumour p. 161 9