1. Cell Division
B-2.6 Summarize the characteristics of the cell cycle: interphase (called G1, S, G2); the phases of mitosis (called prophase, metaphase, anaphase, and telophase); and plant and animal cytokinesis.

2. The Cell Cycle Draw a large circle on your page
Divide into 4 parts like this:

3. G1 G2 S G0 C M A T P Interphase: G1 Phase (Growth) S Phase (Synthesis)
M Phase (Mitosis)
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis C M A T P G1 G2 S G0

5. The Cell Cycle

6. The Cell Cycle

8. INTERPHASE G1 Phase S Phase G2 Phase Cell grows, makes proteins
DNA replicates (synthesizes)
G2 Phase
Growing, getting ready for cell division

9. INTERPHASE

10. M Phase: MITOSIS Prophase Longest phase (50-60% of mitosis)
Chromatin condenses into chromosomes, becomes visible
Nuclear membrane disappears
Centrioles separate to opposite poles
Spindle fibers form, grow toward center
Longest phase (50-60% of mitosis)

11. Prophase:

12. A little about CHROMOSOMES…
In Interphase, DNA in long thin threads, called CHROMATIN. Here, in S phase, they duplicate (replicate, synthesize)
As Prophase begins, CHROMATIN winds up (condenses) into Chromosomes.
Made of two sister Chromatids, joined at the Centromere.

13. A duplicated chromosome:

14. This is interphase’s chromatin, long thin strands of proteins and DNA
This is interphase’s chromatin, long thin strands of proteins and DNA. Only later in mitosis’ beginning, Prophase, will this condense and coil up into the classic looking X shaped structures, termed chromosomes.
Coiled chromosomes

16. M Phase: MITOSIS Metaphase Shortest phase of mitosis
Chromosomes line up at cell’s equator
Spindle fibers connect to chrom.
Shortest phase of mitosis

17. Metaphase:

18. M Phase: MITOSIS Anaphase
Centromeres that join the sister chromatids split
Sister chromatids separate, becoming individual chrom.
They now move to opposites sides of cell

19. Anaphase:

20. M Phase: MITOSIS Telophase Chromosomes uncoil, disappear
Nuclear envelope reforms
Spindle fibers break down
Cytokinesis begins

21. Telophase:

22. M Phase: MITOSIS Cytokinesis: Cytoplasm division
In animals, cleavage furrow pinches cell in two.
In plants, a cell plate forms, becoming the new wall.

23. Cytokinesis: animal
Cleavage furrow

24. Cytokinesis: plants

25. M Phase: MITOSIS

26. Practice