1. The Cell Cycle

2. What are your cells doing right now? Your body is made of trillions of cells At any given point approximately 1 million of your cells are dividing. The rest of your cells are growing or just carrying out their functions Your cellsTheir functions Red blood cellsCarry oxygen White blood cellsFight infection by killing intruders (viruses and bacteria) Muscle cellsContract and relax Intestine cellsAbsorption of nutrients

3. Cell Cycle

7. PhaseWhat happens in this phase? Interphase -Working and growing -Cell duplicates all organelles -Cell duplicates DNA to forms two identical pairs called sister chromatids Prophase

8. PhaseWhat happens in this phase? Interphase -Working and growing -Cell duplicates all organelles -Cell duplicates DNA to forms two identical pairs called sister chromatids Prophase - First stage of mitosis (Cell Division) - Sister chromatids bunch together - sister chromatids join near the center to form an “x” shape (each side of the x is a sister chromatid) - Nuclear membrane starts to break down - Centrioles move to opposite ends of the cell - Spindles (fibres) grow from the centrioles towards the chromatids

9. PhaseWhat happens in this phase? Metaphase - The sister chromatids line up along the center of the cell - Each spindle connects to one of the sister chromatids Anaphase

10. PhaseWhat happens in this phase? Metaphase - The sister chromatids line up along the center of the cell - Each spindle connects to one of the sister chromatids - Anaphase - Sister chromatids are pulled apart by the spindles - Each one of the sister chromatids is pulled to each side of the cell - cleavage furrow forms (the cell membrane is pinching into two cells) Chromatids are called chromosomes after this point

11. PhaseWhat happens in this phase? Telophase - The new chromosomes have reached the opposite ends of the cell - 2 nuclear membranes form - The chromosomes unravel - The spindle disappears - nucleolus reforms Cytokinesis

12. PhaseWhat happens in this phase? Telophase - The new chromosomes have reached the opposite ends of the cell - 2 nuclear membranes form - The chromosomes unravel - The spindle disappears - nucleolus reforms Cytokinesis - Divides the cytoplasm and organelles - once the cytoplasm is divided the cell pinches in tow You now have two daughter cells