1. The Cell Cycle & Cell Division

2. The Cell Cycle
Most cells in an organism go through a cycle of growth, development, and division called the cell cycle.
The cell cycle allows organisms :
to grow and develop
replace old or damaged cells
produce new cells.

3. Phases Of The Cell Cycle
There are two main phases of the cell cycle:
Interphase
Mitotic phase

4. Interphase
Interphase is a period of growth and development for a cell.
It makes up most of the cell cycle
During interphase, The DNA of the cell is called chromatin

5. Interphase During interphase, cells go through three stages:
1. Rapid growth and replication of the organelles. (G1 stage)

6. Interphase 2. Replication of DNA . (S stage)
The cell replicates its strands of chromatin
Sister chromatids are the two identical strands of DNA that make up the duplicated chromosome.
They are held together by a structure called a centromere.

7. Interphase
3. Growth and final preparation for cell division (G2 Stage

8. Mitotic Phase
Mitosis- The process of cell division that results in 2 identical cells(daughter cells) with the same number of chromosomes.
Only happens in body cells
Sub-stages of Mitosis:
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

9. Prophase
Duplicated DNA condenses into chromosomes

10. Metaphase
Chromosomes line up in the middle of the cell

11. Anaphase
Sister chromatids in each duplicated chromosome separate and are pulled in opposite directions by the spindle fibers

12. Telophase
Chromosomes begin to uncoil, and 2 new identical nuclei form

13. Cytokinesis
Cytokinesis divides a cell’s cytoplasm forming a new cell membrane around each daughter cell.
In animal cells , a furrow in the middle of the cell gets deeper until the cell membrane comes together to divide the cell.

14. Cytokinesis
In plants, a cell plate grows outward toward a new cell wall until 2 new cells form

15. The cell cycle is important for :
for reproduction in some organisms
growth in multi-cellular organisms
replacement of worn-out or damaged cells
Repair of damaged tissues