1. Unit 6: Cell Growth and Development 6.4 Mitosis

2. Mitosis
Division of duplicated chromosomes into two new SOMATIC daughter cells.

3. Prophase: Genetic material inside the nucleus condenses and the duplicated chromosomes become visible. Outside the nucleus, a spindle starts to form.
Longest phase of mitosis
Chromatin is compacted into visible chromosomes
Chromosomes pair up
Cell starts to build a spindle (microtubules) that will help separate duplicated chromosomes
Nuclear envelope disappears
Stage 1 of Mitosis

4. Metaphase: Centromeres of duplicated chromosomes line-up across the center of the cell. Spindle fibers connect the centromere of each chromosome to the two poles of the spindle
Chromosomes line up in the middle (equatorial plane) of the cell
Spindle fibers link at centromeres
Stage 2 of Mitosis

5. Anaphase: Chromosomes (chromatids) separate and move along spindle fibers to the opposite end of the cell.
Anaphase ends when this movement stops and the chromosomes are in two separate groups.
Stage 3 of Mitosis

6. Telophase: Chromosomes begin to spread into a tangle of chromatin.
Nuclear envelope re-forms around two nuclei
Spindle breaks apart
Nucleolus becomes visible in each daughter cell
Stage 4 of Mitosis

8. Cytokinesis
Splits one cell into two, completing the process of cell division.
Different in plant and animal cells
Animal cells: cell membrane is drawn inward until pinched in two
Plant cells: cell plate forms halfway between

9. Cytokinesis