Presentation on theme: "CELL CYCLE 11-11-08. Cell Growth Body cells spend most of its life growing and doing work. But it can only grow so large. Body cells consist of skin,"— Presentation transcript:
Cell Growth Body cells spend most of its life growing and doing work. But it can only grow so large. Body cells consist of skin, stomach, & blood cells Growth in an organism occurs because of adding cells.
Cell Division Cells will eventually reach a stage in their cell cycle and will divide. This process of cell division is called MITOSIS. Mitosis- a process of cell division in body cells. One parent cell produces two daughter cells.
Cell Cycle A series of events a cell goes through as it divides and grows. Interphase- time between cell divisions when the cell is growing and working. The cell is in interphase for 99% of its life. The cell is undergoing mitosis (dividing) the rest of the time The cell cycle is divided into 4 phases
Cell Cycle Phases 1. G 1 phase- Cell Growth: “Gap” time in which cell grows the most; makes proteins. 2. S phase- DNA Replication: Chromosomes are copied; begins to prepare for mitosis
Cell Cycle Phases 3. G 2 phase- Prep for Mitosis: “Gap” Shortest of 3 interphase phases - organelles and molecules needed for mitosis are produced 4. M phase- Mitosis stages and cytokinesis
Checkpoints There are 3 checkpoints in the cycle 1. G1 Checkpoint: If the cell is big enough and the environment is suitable. 2. G2 Checkpoint: If DNA has replicated, the cell is big enough, and the environment is suitable. 3. Metaphase checkpoint: If chromosomes are aligned at the spindle