2. How does the cell know how to divide?
Cell Division
Reproduction
Growth
Repair
Why do cells divide?
How does the cell know how to divide?
The DNA has the instructions for all of the cell’s activities.

3. Cell Cycle 3 Parts The sequence of development and division of a cell
Interphase – Preparation
Mitosis – Cell division
Cytokinesis – Splitting
Adult human cell: ~24 hrs
18-20 hours in interphase
2 hours in mitosis
Embryonic cells: 30 min.
How long does it take?

4. Interphase What happens G1-the cell grows larger
S Phase: DNA replicates (makes copies)
These are called chromatids. Centrioles appear and hold them together
G2-Organelles double in number; the cell is checked for mistakes which are corrected

5. Mitosis: PROPHASE What happens DNA forms chromosomes Spindle forms
Centrioles move toward opposite poles (a clue!)
Nuclear membrane begins to disappear
Draw the final picture

6. Mitosis: METAPHASE What happens Nucleus has disappeared completely
Chromosomes line up in the middle (a clue!) of the cell
Draw the final picture

7. Mitosis: ANAPHASE What happens Centromeres divide
Chromatids separate and move apart (a clue!) to opposite poles
Draw the final picture

8. Mitosis: TELOPHASE What happens
Nuclear membrane forms around each group of chromosomes to begin forming two (a clue!) cells
Chromosomes unwind
Cytokinesis begins
Draw the final picture

9. Cytokinesis What happens
Cytoplasm divides (a clue!) into two cells called daughter cells
Draw the final picture