What happens to old cells?

1. What happens to old cells? Just like us, cells grow old and die. When old cells die, new ones replace them. For example, a blood cell in our body lives for about 120 days. Another example is our skin cells. We shed our skin cells about every 35 days. Don't worry, we do not shed all our skin cells at the same time like snakes do. In human beings, only the skin cells that are old are shed, others are not.  Here is a amazing fact for you, if your skin cells are replaced every 35 days, by the time you are 20 years old you would have replaced your skin cells roughly about 200 times.

2. Mitosis • Also called cell division • -the division of one (parent) cell into two cells (daughter) occurs in stages

3. Phase 1: Interphase • -the cell is performing its everyday life functions • -chromosomes appear as thread like coils called chromatin • - centrioles are outside the nucleus • - at the end of interphase chromosomes double (sister chromosomes)

4. Phase 2: Prophase • - chromatin shorten and form the familiar rod like chromosomes • - sister chromosomes attach to a centromere • - nucleus begins to break down

5. Phase 3: Metaphase • - chromosomes attach to the spindle fiber • - chromosomes line up in the middle of the cell

6. Phase 4: Anaphase • - centromere splits • - sister chromosomes separate and move to opposite sides of the cell

7. Phase 5: Telophase • - two separate nucleus form • - chromosomes uncoil and lose rod like appearance • - chromosomes appear as chromatin

8. Phase 6: Cytokinesis • - division of cytoplasm of cell • - membrane surrounding the cell pinches inward • - each part contains a nucleus with identical chromosomes

9. Stages of Mitosis • Interphase • Prophase • Metaphase • Anaphase • Telephase • Cytokinesis

10. How to remember the stages of Mitosis • I • Promised • Mother • A • Terrific • Card