1. Life of a Cell
The Cell Cycle

2. The Cell Cycle
Consists of:
Interphase
Mitosis
Cytokinesis

3. Interphase
NOT a “resting” phase for the cell. The cell carries out metabolic processes and prepares for cell division during interphase.
G1: Cell growth
S: DNA is replicated (46 chromosomes in humans)
G2: Cell growth

4. Interphase (Plant)

5. Interphase (Animal)
Cell membrane
Nuclear membrane

6. Mitosis Process that divides the nucleus of a cell
Purpose is to create two daughter cells with identical information
Growth and development and/or repair of tissue
Each daughter cell receives the exact same # and type of chromosomes
Consists of 4 phases:
Prophase
Metaphase
Anaphase
Telophase

7. Prophase Illustration
In prophase:
Nuclear membrane disintegrates (disappears)
Chromatin coils into chromosomes and becomes visible
Chromosomes consist of 2 chromatids
Centrosomes migrate to opposite sides of cell; spindle fibers form and attach to chromosomes
Centrosomes

8. Prophase (Plant)
Chromatin is condensing into chromosomes

9. Prophase (Animal)
Chromosomes

10. Metaphase Illustration
Centromere
Centriole
*Chromosomes still consist of two chromatids

11. Metaphase (Plant)

12. Metaphase (Animal)

13. Anaphase Illustration
In Anaphase:
Chromatids separate at the centromere, becoming individual chromosomes
Chromosome now = 1 chromatid
Spindle fibers shorten, pulling chromatids to opposite poles of cell
Centriole
Spindle Fibers
Chromatid
Centromere

14. Anaphase (Plant)
Chromatids

15. Anaphase (Animal)
Chromatid
Centriole

16. Telophase Illustration
In telophase:
Nuclear membrane forms again
Chromosomes uncoil into long strands of chromatin
Cytokinesis begins

17. Telophase (Plant)
Nuclear membrane forming
Chromatin

18. Telophase (Animal)
Nucleus

19. Cytokinesis Illustration
In cytokinesis:
The cytoplasm divides between the daughter cells
Happens by cleavage furrow (animal) or formation of cell plate (plant)
Produces 2 daughter cells
Cleavage furrow

20. Cytokinesis (Plant)

21. Cytokinesis (Animal)
Cleavage Furrow